diff --git a/docs/implplan/SPRINT_20260310_006_FE_policy_simulation_direct_route_defaults_and_hydration.md b/docs/implplan/SPRINT_20260310_006_FE_policy_simulation_direct_route_defaults_and_hydration.md
new file mode 100644
index 000000000..9870de0c8
--- /dev/null
+++ b/docs/implplan/SPRINT_20260310_006_FE_policy_simulation_direct_route_defaults_and_hydration.md
@@ -0,0 +1,50 @@
+# Sprint 20260310-006 - FE Policy Simulation Direct Route Defaults and Hydration
+
+## Topic & Scope
+- Harden revived Policy Simulation surfaces so direct entry and partially wired host routes still render usable defaults instead of blank inputs.
+- Normalize missing policy pack, version, and target environment inputs across the revived lint, diff, coverage, and promotion-gate components.
+- Ensure the read-only coverage route hydrates on first render instead of waiting for a second interaction.
+- Working directory: `src/Web/StellaOps.Web/src/app/features/policy-simulation`.
+- Allowed coordination edits: `src/Web/StellaOps.Web/tsconfig.spec.features.json`, `docs/modules/ui/README.md`.
+- Expected evidence: focused component spec pass, authenticated live Playwright evidence for `/ops/policy/simulation` policy actions, updated UI docs if behavior changes.
+
+## Dependencies & Concurrency
+- Follows `SPRINT_20260309_019_FE_policy_simulation_active_tenant_runtime.md`; this sprint hardens the revived component surfaces after the tenant seam repair.
+- Safe parallelism: do not touch router readiness or unrelated search work while closing this slice.
+
+## Documentation Prerequisites
+- `AGENTS.md`
+- `docs/code-of-conduct/CODE_OF_CONDUCT.md`
+- `docs/qa/feature-checks/FLOW.md`
+- `docs/modules/ui/README.md`
+
+## Delivery Tracker
+
+### FE-POLICY-SIM-006-001 - Normalize revived policy simulation inputs and direct hydration
+Status: DONE
+Dependency: none
+Owners: Developer, QA
+Task description:
+- Centralize the fallback defaults used by revived Policy Simulation components so direct-entry routes and partially restored host callers do not pass through blank pack IDs, unusable versions, or empty target environments.
+- Cover the normalization behavior in focused specs for the shared defaults helper and the affected components, then re-run live authenticated policy actions with Playwright to prove the repaired runtime still behaves correctly.
+
+Completion criteria:
+- [x] Coverage, diff, lint, and promotion-gate components normalize missing/blank inputs to stable defaults instead of rendering unusable state.
+- [x] Coverage auto-loads on first render so the direct route is hydrated without a second click.
+- [x] Focused Angular specs prove the normalization and hydration behaviors.
+- [x] Authenticated Playwright completes the policy action sweep on `https://stella-ops.local` without new route or runtime failures.
+
+## Execution Log
+| Date (UTC) | Update | Owner |
+| --- | --- | --- |
+| 2026-03-10 | Sprint created after the remaining dirty `policy-simulation` slice was identified as a follow-on hardening pass for revived direct-route component defaults and coverage hydration. | Developer |
+| 2026-03-10 | Added shared policy simulation defaults plus a Vitest-compatible direct-route regression harness, rebuilt the web bundle, synced `dist/stellaops-web/browser` into `compose_console-dist`, and verified `/ops/policy/simulation/coverage`, `/lint`, `/promotion`, and `/diff/policy-pack-001` live with zero runtime errors via Playwright. | Developer |
+
+## Decisions & Risks
+- Decision: keep default restoration local to the revived Policy Simulation feature cluster through a shared helper instead of reintroducing per-component literals.
+- Decision: use a focused Vitest-compatible regression spec for the revived direct-route behaviors instead of widening the unsupported legacy ProxyZone/Karma component suite.
+- Risk: defaulting a missing pack/version can hide a wiring regression; mitigate with focused specs and live Playwright verification on the real shell.
+
+## Next Checkpoints
+- 2026-03-10: finish the focused spec coverage and live policy Playwright recheck.
+- 2026-03-10: commit the isolated policy-simulation hardening slice.
diff --git a/docs/modules/ui/README.md b/docs/modules/ui/README.md
index f9409ba3a..ef3d7f070 100644
--- a/docs/modules/ui/README.md
+++ b/docs/modules/ui/README.md
@@ -8,6 +8,11 @@
 
 The Console presents operator dashboards for scans, policies, VEX evidence, runtime posture, and admin workflows.
 
+## Latest updates (2026-03-10)
+- Hardened revived `Ops > Policy > Simulation` direct-entry surfaces so coverage, lint, promotion-gate, and diff routes restore stable defaults when host wiring omits pack/version/environment inputs.
+- Coverage now hydrates on first render instead of waiting for a second interaction, preventing blank direct-route states on `/ops/policy/simulation/coverage`.
+- Added focused frontend verification for the policy simulation defaults helper and direct-route behaviors, plus a live Playwright sweep for `/ops/policy/simulation/coverage`, `/lint`, `/promotion`, and `/diff/policy-pack-001`.
+
 ## Latest updates (2026-03-08)
 - Shipped the canonical `Releases > Promotions` cutover, including repaired `/release-control/promotions*` and `/releases/promotion-queue*` aliases, release-context promotion wizard handoff, and a usable create-to-detail flow.
 - Added checked-feature verification for release promotions at `../../features/checked/web/release-promotions-cutover-ui.md`.
diff --git a/src/Web/StellaOps.Web/scripts/live-policy-simulation-direct-routes.mjs b/src/Web/StellaOps.Web/scripts/live-policy-simulation-direct-routes.mjs
new file mode 100644
index 000000000..771acaab4
--- /dev/null
+++ b/src/Web/StellaOps.Web/scripts/live-policy-simulation-direct-routes.mjs
@@ -0,0 +1,221 @@
+#!/usr/bin/env node
+
+import { mkdirSync, writeFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { chromium } from 'playwright';
+
+import { authenticateFrontdoor, createAuthenticatedContext } from './live-frontdoor-auth.mjs';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const webRoot = path.resolve(__dirname, '..');
+const outputDirectory = path.join(webRoot, 'output', 'playwright');
+
+const DEFAULT_BASE_URL = process.env.STELLAOPS_FRONTDOOR_BASE_URL?.trim() || 'https://stella-ops.local';
+const authStatePath = path.join(outputDirectory, 'live-policy-simulation-direct-routes.auth.json');
+const authReportPath = path.join(outputDirectory, 'live-policy-simulation-direct-routes.auth-report.json');
+const summaryPath = path.join(outputDirectory, 'live-policy-simulation-direct-routes.json');
+
+function isStaticAsset(url) {
+  return /\.(?:css|js|map|png|jpg|jpeg|svg|woff2?|ico)(?:$|\?)/i.test(url);
+}
+
+function shouldIgnoreFailure(errorText) {
+  return errorText === 'net::ERR_ABORTED';
+}
+
+function createRuntime() {
+  return {
+    consoleErrors: [],
+    pageErrors: [],
+    requestFailures: [],
+    responseErrors: [],
+  };
+}
+
+function attachRuntimeWatchers(page, runtime) {
+  page.on('console', (message) => {
+    if (message.type() === 'error') {
+      runtime.consoleErrors.push({
+        page: page.url(),
+        text: message.text(),
+      });
+    }
+  });
+
+  page.on('pageerror', (error) => {
+    runtime.pageErrors.push({
+      page: page.url(),
+      message: error.message,
+    });
+  });
+
+  page.on('requestfailed', (request) => {
+    const url = request.url();
+    const errorText = request.failure()?.errorText ?? 'unknown';
+    if (isStaticAsset(url) || shouldIgnoreFailure(errorText)) {
+      return;
+    }
+
+    runtime.requestFailures.push({
+      page: page.url(),
+      method: request.method(),
+      url,
+      error: errorText,
+    });
+  });
+
+  page.on('response', (response) => {
+    const url = response.url();
+    if (isStaticAsset(url) || response.status() < 400) {
+      return;
+    }
+
+    runtime.responseErrors.push({
+      page: page.url(),
+      method: response.request().method(),
+      status: response.status(),
+      url,
+    });
+  });
+}
+
+async function waitForAnyVisible(page, selectors, timeout = 10_000) {
+  const deadline = Date.now() + timeout;
+  while (Date.now() < deadline) {
+    for (const selector of selectors) {
+      if (await page.locator(selector).first().isVisible().catch(() => false)) {
+        return selector;
+      }
+    }
+    await page.waitForTimeout(200);
+  }
+  throw new Error(`Timed out waiting for any selector: ${selectors.join(', ')}`);
+}
+
+async function checkRoute(page, baseUrl, route) {
+  const startedAt = new Date().toISOString();
+  let ok = false;
+  let error = null;
+
+  try {
+    await page.goto(`${baseUrl}${route.path}`, {
+      waitUntil: 'domcontentloaded',
+      timeout: 30_000,
+    });
+    await page.waitForLoadState('networkidle', { timeout: 15_000 }).catch(() => {});
+    await waitForAnyVisible(page, route.expectVisible);
+
+    if (route.action) {
+      await route.action(page);
+    }
+
+    ok = true;
+  } catch (cause) {
+    error = cause instanceof Error ? cause.message : String(cause);
+  }
+
+  return {
+    route: route.path,
+    ok,
+    startedAtUtc: startedAt,
+    finishedAtUtc: new Date().toISOString(),
+    finalUrl: page.url(),
+    error,
+  };
+}
+
+async function main() {
+  mkdirSync(outputDirectory, { recursive: true });
+
+  const authReport = await authenticateFrontdoor({
+    baseUrl: DEFAULT_BASE_URL,
+    statePath: authStatePath,
+    reportPath: authReportPath,
+    headless: true,
+  });
+
+  const browser = await chromium.launch({
+    headless: true,
+    args: ['--disable-dev-shm-usage'],
+  });
+
+  const context = await createAuthenticatedContext(browser, authReport, {
+    statePath: authStatePath,
+  });
+  const page = await context.newPage();
+  const runtime = createRuntime();
+  attachRuntimeWatchers(page, runtime);
+
+  const routes = [
+    {
+      path: '/ops/policy/simulation/coverage',
+      expectVisible: ['h1:has-text("Test Coverage")', '.coverage__header'],
+      action: async (routePage) => {
+        await waitForAnyVisible(routePage, ['.coverage__summary', '.coverage__rules']);
+      },
+    },
+    {
+      path: '/ops/policy/simulation/lint',
+      expectVisible: ['h1:has-text("Policy Lint")', '.policy-lint__header'],
+      action: async (routePage) => {
+        await routePage.getByRole('button', { name: /run lint/i }).click();
+        await waitForAnyVisible(routePage, ['.lint-status', '.lint-summary']);
+      },
+    },
+    {
+      path: '/ops/policy/simulation/promotion',
+      expectVisible: ['h1:has-text("Promotion Gate")', '.promotion-gate__header'],
+      action: async (routePage) => {
+        await routePage.getByRole('button', { name: /check requirements/i }).click();
+        await waitForAnyVisible(routePage, ['.promotion-gate__info', '.promotion-gate__summary']);
+      },
+    },
+    {
+      path: '/ops/policy/simulation/diff/policy-pack-001',
+      expectVisible: ['h1:has-text("Policy Diff")', '.diff-viewer__header'],
+      action: async (routePage) => {
+        await waitForAnyVisible(routePage, ['.diff-viewer__stats', '.diff-viewer__empty', '.diff-viewer__files']);
+      },
+    },
+  ];
+
+  const results = [];
+  try {
+    for (const route of routes) {
+      results.push(await checkRoute(page, DEFAULT_BASE_URL, route));
+    }
+  } finally {
+    await context.close().catch(() => {});
+    await browser.close().catch(() => {});
+  }
+
+  const summary = {
+    capturedAtUtc: new Date().toISOString(),
+    baseUrl: DEFAULT_BASE_URL,
+    results,
+    runtime,
+    failedRouteCount: results.filter((result) => result.ok === false).length,
+    runtimeIssueCount:
+      runtime.consoleErrors.length +
+      runtime.pageErrors.length +
+      runtime.requestFailures.length +
+      runtime.responseErrors.length,
+  };
+
+  writeFileSync(summaryPath, `${JSON.stringify(summary, null, 2)}\n`, 'utf8');
+  process.stdout.write(`${JSON.stringify(summary, null, 2)}\n`);
+
+  if (summary.failedRouteCount > 0 || summary.runtimeIssueCount > 0) {
+    process.exitCode = 1;
+  }
+}
+
+main().catch((error) => {
+  process.stderr.write(
+    `[live-policy-simulation-direct-routes] ${error instanceof Error ? error.message : String(error)}\n`,
+  );
+  process.exitCode = 1;
+});
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.spec.ts
index f07fb4cd1..9daa55f78 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.spec.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.spec.ts
@@ -80,7 +80,7 @@ describe('CoverageFixtureComponent', () => {
     mockApi = jasmine.createSpyObj('PolicySimulationApi', [
       'getCoverage',
       'runCoverageTests',
-    ]);
+    ]) as jasmine.SpyObj<PolicySimulationApi>;
     mockApi.getCoverage.and.returnValue(of(mockCoverageResult));
     mockApi.runCoverageTests.and.returnValue(of(mockCoverageResult));
 
@@ -127,6 +127,11 @@ describe('CoverageFixtureComponent', () => {
       expect(component.policyPackId).toBe('custom-pack');
     });
 
+    it('should restore the default policy pack id when routing supplies undefined', () => {
+      component.policyPackId = undefined as unknown as string;
+      expect(component.policyPackId).toBe('policy-pack-001');
+    });
+
     it('should accept policyVersion input', () => {
       component.policyVersion = 2;
       expect(component.policyVersion).toBe(2);
@@ -158,6 +163,13 @@ describe('CoverageFixtureComponent', () => {
   });
 
   describe('Service Interaction', () => {
+    it('should load coverage on init so direct routes are hydrated', fakeAsync(() => {
+      fixture.detectChanges();
+      tick();
+
+      expect(mockApi.getCoverage).toHaveBeenCalled();
+    }));
+
     it('should call getCoverage on loadCoverage', fakeAsync(() => {
       component.loadCoverage();
       tick();
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.ts
index 05b3f8104..4423fedbb 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/coverage-fixture.component.ts
@@ -1,5 +1,5 @@
 import { CommonModule } from '@angular/common';
-import { Component, ChangeDetectionStrategy, inject, signal, computed, Input, OnChanges, SimpleChanges } from '@angular/core';
+import { Component, ChangeDetectionStrategy, inject, signal, computed, Input, OnChanges, OnInit, SimpleChanges } from '@angular/core';
 
 import { finalize } from 'rxjs/operators';
 
@@ -13,6 +13,11 @@ import {
   PolicyTestCase,
   CoverageStatus,
 } from '../../core/api/policy-simulation.models';
+import {
+  DEFAULT_POLICY_PACK_ID,
+  normalizeOptionalPolicyVersion,
+  normalizePolicyPackId,
+} from './policy-simulation-defaults';
 
 /**
  * Coverage fixture component showing coverage percentage per rule and missing test cases.
@@ -724,11 +729,28 @@ import {
     `,
     ]
 })
-export class CoverageFixtureComponent implements OnChanges {
+export class CoverageFixtureComponent implements OnChanges, OnInit {
   private readonly api = inject(POLICY_SIMULATION_API);
+  private _policyPackId = DEFAULT_POLICY_PACK_ID;
+  private _policyVersion: number | undefined;
 
-  @Input() policyPackId = 'policy-pack-001';
-  @Input() policyVersion?: number;
+  @Input()
+  set policyPackId(value: string | null | undefined) {
+    this._policyPackId = normalizePolicyPackId(value);
+  }
+
+  get policyPackId(): string {
+    return this._policyPackId;
+  }
+
+  @Input()
+  set policyVersion(value: number | string | null | undefined) {
+    this._policyVersion = normalizeOptionalPolicyVersion(value);
+  }
+
+  get policyVersion(): number | undefined {
+    return this._policyVersion;
+  }
 
   readonly loading = signal(false);
   readonly result = signal<CoverageResult | undefined>(undefined);
@@ -755,6 +777,12 @@ export class CoverageFixtureComponent implements OnChanges {
     }
   }
 
+  ngOnInit(): void {
+    if (!this.loading() && !this.result()) {
+      this.loadCoverage();
+    }
+  }
+
   ringDashArray(): string {
     const circumference = 2 * Math.PI * 54; // ~339.3
     const percent = this.result()?.summary.overallCoveragePercent ?? 0;
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.spec.ts
index ee4d9e1dc..4f20ee899 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.spec.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.spec.ts
@@ -57,7 +57,7 @@ describe('PolicyDiffViewerComponent', () => {
   };
 
   beforeEach(async () => {
-    mockApi = jasmine.createSpyObj('PolicySimulationApi', ['getDiff']);
+    mockApi = jasmine.createSpyObj('PolicySimulationApi', ['getDiff']) as jasmine.SpyObj<PolicySimulationApi>;
     mockApi.getDiff.and.returnValue(of(mockDiffResult));
 
     await TestBed.configureTestingModule({
@@ -93,6 +93,11 @@ describe('PolicyDiffViewerComponent', () => {
       expect(component.policyPackId).toBe('custom-pack');
     });
 
+    it('should restore the default policy pack id when routing supplies undefined', () => {
+      (component as any).policyPackId = undefined;
+      expect(component.policyPackId).toBe('policy-pack-001');
+    });
+
     it('should accept fromVersion input', () => {
       component.fromVersion = 1;
       expect(component.fromVersion).toBe(1);
@@ -103,6 +108,14 @@ describe('PolicyDiffViewerComponent', () => {
       expect(component.toVersion).toBe(3);
     });
 
+    it('should restore version fallbacks when routing supplies unusable values', () => {
+      (component as any).fromVersion = '';
+      (component as any).toVersion = '0';
+
+      expect(component.fromVersion).toBe(1);
+      expect(component.toVersion).toBe(2);
+    });
+
     it('should load diff on policyPackId change', fakeAsync(() => {
       component.ngOnChanges({
         policyPackId: new SimpleChange(null, 'new-pack', true),
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.ts
index 1fbcfa034..0a648ba4c 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-diff-viewer.component.ts
@@ -13,6 +13,11 @@ import {
   PolicyDiffHunk,
   PolicyDiffLine,
 } from '../../core/api/policy-simulation.models';
+import {
+  DEFAULT_POLICY_PACK_ID,
+  normalizePolicyPackId,
+  normalizePolicyVersion,
+} from './policy-simulation-defaults';
 
 /**
  * Policy diff viewer showing before/after comparison for rule changes.
@@ -477,10 +482,36 @@ import {
 })
 export class PolicyDiffViewerComponent implements OnChanges {
   private readonly api = inject(POLICY_SIMULATION_API);
+  private _policyPackId = DEFAULT_POLICY_PACK_ID;
+  private _fromVersion = 1;
+  private _toVersion = 2;
 
-  @Input() policyPackId = 'policy-pack-001';
-  @Input() fromVersion = 1;
-  @Input() toVersion = 2;
+  @Input()
+  set policyPackId(value: string | null | undefined) {
+    this._policyPackId = normalizePolicyPackId(value);
+  }
+
+  get policyPackId(): string {
+    return this._policyPackId;
+  }
+
+  @Input()
+  set fromVersion(value: number | string | null | undefined) {
+    this._fromVersion = normalizePolicyVersion(value, 1);
+  }
+
+  get fromVersion(): number {
+    return this._fromVersion;
+  }
+
+  @Input()
+  set toVersion(value: number | string | null | undefined) {
+    this._toVersion = normalizePolicyVersion(value, 2);
+  }
+
+  get toVersion(): number {
+    return this._toVersion;
+  }
 
   readonly loading = signal(false);
   readonly result = signal<PolicyDiffResult | undefined>(undefined);
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.spec.ts
index cfc6ba248..be372ca92 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.spec.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.spec.ts
@@ -76,7 +76,7 @@ describe('PolicyLintComponent', () => {
   };
 
   beforeEach(async () => {
-    mockApi = jasmine.createSpyObj('PolicySimulationApi', ['lintPolicy']);
+    mockApi = jasmine.createSpyObj('PolicySimulationApi', ['lintPolicy']) as jasmine.SpyObj<PolicySimulationApi>;
     mockApi.lintPolicy.and.returnValue(of(mockLintResult));
 
     await TestBed.configureTestingModule({
@@ -125,11 +125,21 @@ describe('PolicyLintComponent', () => {
       expect(component.policyPackId).toBe('custom-pack');
     });
 
+    it('should restore the default policy pack id when routing supplies undefined', () => {
+      (component as any).policyPackId = undefined;
+      expect(component.policyPackId).toBe('policy-pack-001');
+    });
+
     it('should accept policyVersion input', () => {
       component.policyVersion = 2;
       expect(component.policyVersion).toBe(2);
     });
 
+    it('should clear policyVersion when routing supplies an unusable value', () => {
+      (component as any).policyVersion = '0';
+      expect(component.policyVersion).toBeUndefined();
+    });
+
     it('should clear result on input change', fakeAsync(() => {
       component['result'].set(mockLintResult);
       component.ngOnChanges({
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.ts
index a52aad99a..62b704570 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-lint.component.ts
@@ -13,6 +13,11 @@ import {
   LintSeverity,
   LintCategory,
 } from '../../core/api/policy-simulation.models';
+import {
+  DEFAULT_POLICY_PACK_ID,
+  normalizeOptionalPolicyVersion,
+  normalizePolicyPackId,
+} from './policy-simulation-defaults';
 
 /**
  * Policy lint component showing errors, warnings, and compilation status.
@@ -593,9 +598,26 @@ import {
 })
 export class PolicyLintComponent implements OnChanges {
   private readonly api = inject(POLICY_SIMULATION_API);
+  private _policyPackId = DEFAULT_POLICY_PACK_ID;
+  private _policyVersion: number | undefined;
 
-  @Input() policyPackId = 'policy-pack-001';
-  @Input() policyVersion?: number;
+  @Input()
+  set policyPackId(value: string | null | undefined) {
+    this._policyPackId = normalizePolicyPackId(value);
+  }
+
+  get policyPackId(): string {
+    return this._policyPackId;
+  }
+
+  @Input()
+  set policyVersion(value: number | string | null | undefined) {
+    this._policyVersion = normalizeOptionalPolicyVersion(value);
+  }
+
+  get policyVersion(): number | undefined {
+    return this._policyVersion;
+  }
 
   readonly loading = signal(false);
   readonly result = signal<PolicyLintResult | undefined>(undefined);
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.spec.ts
new file mode 100644
index 000000000..361093c2b
--- /dev/null
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.spec.ts
@@ -0,0 +1,41 @@
+import {
+  DEFAULT_POLICY_PACK_ID,
+  DEFAULT_POLICY_VERSION,
+  DEFAULT_TARGET_ENVIRONMENT,
+  normalizeOptionalPolicyVersion,
+  normalizePolicyPackId,
+  normalizePolicyVersion,
+  normalizeTargetEnvironment,
+} from './policy-simulation-defaults';
+
+describe('policy simulation input defaults', () => {
+  it('falls back to the default policy pack id when the router supplies an empty value', () => {
+    expect(normalizePolicyPackId(undefined)).toBe(DEFAULT_POLICY_PACK_ID);
+    expect(normalizePolicyPackId('')).toBe(DEFAULT_POLICY_PACK_ID);
+    expect(normalizePolicyPackId('   ')).toBe(DEFAULT_POLICY_PACK_ID);
+  });
+
+  it('keeps valid policy pack ids untouched', () => {
+    expect(normalizePolicyPackId('policy-pack-prod-001')).toBe('policy-pack-prod-001');
+  });
+
+  it('parses optional positive policy versions and rejects invalid values', () => {
+    expect(normalizeOptionalPolicyVersion('7')).toBe(7);
+    expect(normalizeOptionalPolicyVersion(3)).toBe(3);
+    expect(normalizeOptionalPolicyVersion(undefined)).toBeUndefined();
+    expect(normalizeOptionalPolicyVersion('0')).toBeUndefined();
+    expect(normalizeOptionalPolicyVersion('abc')).toBeUndefined();
+  });
+
+  it('restores default numeric values when routing supplies nothing usable', () => {
+    expect(normalizePolicyVersion(undefined, DEFAULT_POLICY_VERSION)).toBe(DEFAULT_POLICY_VERSION);
+    expect(normalizePolicyVersion('', DEFAULT_POLICY_VERSION)).toBe(DEFAULT_POLICY_VERSION);
+    expect(normalizePolicyVersion('5', DEFAULT_POLICY_VERSION)).toBe(5);
+  });
+
+  it('restores the default target environment when the route has no environment segment', () => {
+    expect(normalizeTargetEnvironment(undefined)).toBe(DEFAULT_TARGET_ENVIRONMENT);
+    expect(normalizeTargetEnvironment('')).toBe(DEFAULT_TARGET_ENVIRONMENT);
+    expect(normalizeTargetEnvironment('stage')).toBe('stage');
+  });
+});
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.ts
new file mode 100644
index 000000000..591dc8b02
--- /dev/null
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-defaults.ts
@@ -0,0 +1,33 @@
+export const DEFAULT_POLICY_PACK_ID = 'policy-pack-001';
+export const DEFAULT_POLICY_VERSION = 2;
+export const DEFAULT_TARGET_ENVIRONMENT = 'production';
+
+export function normalizePolicyPackId(value: string | null | undefined): string {
+  const normalized = value?.trim();
+  return normalized ? normalized : DEFAULT_POLICY_PACK_ID;
+}
+
+export function normalizeOptionalPolicyVersion(value: number | string | null | undefined): number | undefined {
+  if (value === null || value === undefined || value === '') {
+    return undefined;
+  }
+
+  const numericValue = typeof value === 'number' ? value : Number(value);
+  if (!Number.isFinite(numericValue) || numericValue <= 0) {
+    return undefined;
+  }
+
+  return Math.trunc(numericValue);
+}
+
+export function normalizePolicyVersion(
+  value: number | string | null | undefined,
+  fallback: number,
+): number {
+  return normalizeOptionalPolicyVersion(value) ?? fallback;
+}
+
+export function normalizeTargetEnvironment(value: string | null | undefined): string {
+  const normalized = value?.trim();
+  return normalized ? normalized : DEFAULT_TARGET_ENVIRONMENT;
+}
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-direct-route-defaults.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-direct-route-defaults.spec.ts
new file mode 100644
index 000000000..1c65343bf
--- /dev/null
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/policy-simulation-direct-route-defaults.spec.ts
@@ -0,0 +1,204 @@
+import { SimpleChange } from '@angular/core';
+import { TestBed } from '@angular/core/testing';
+import { provideRouter } from '@angular/router';
+import { of } from 'rxjs';
+
+import { POLICY_SIMULATION_API, PolicySimulationApi } from '../../core/api/policy-simulation.client';
+import {
+  CoverageResult,
+  PolicyDiffResult,
+  PolicyLintResult,
+  PromotionGateResult,
+} from '../../core/api/policy-simulation.models';
+import { CoverageFixtureComponent } from './coverage-fixture.component';
+import { PolicyDiffViewerComponent } from './policy-diff-viewer.component';
+import { PolicyLintComponent } from './policy-lint.component';
+import { PromotionGateComponent } from './promotion-gate.component';
+
+function createPolicySimulationApiMock(): jasmine.SpyObj<PolicySimulationApi> {
+  return jasmine.createSpyObj('PolicySimulationApi', [
+    'getCoverage',
+    'runCoverageTests',
+    'getDiff',
+    'lintPolicy',
+    'checkPromotionGate',
+    'overridePromotionGate',
+  ]) as jasmine.SpyObj<PolicySimulationApi>;
+}
+
+const coverageResult: CoverageResult = {
+  summary: {
+    policyPackId: 'policy-pack-001',
+    policyVersion: 1,
+    totalRules: 1,
+    coveredRules: 1,
+    partialRules: 0,
+    uncoveredRules: 0,
+    overallCoveragePercent: 100,
+    totalTestCases: 1,
+    passedTestCases: 1,
+    failedTestCases: 0,
+    computedAt: '2026-03-10T00:00:00Z',
+  },
+  rules: [],
+  testCases: [],
+  traceId: 'trace-coverage',
+};
+
+const diffResult: PolicyDiffResult = {
+  diffId: 'diff-001',
+  policyPackId: 'policy-pack-001',
+  fromVersion: 1,
+  toVersion: 2,
+  files: [],
+  stats: { additions: 0, deletions: 0, modifications: 0, filesChanged: 0 },
+  createdAt: '2026-03-10T00:00:00Z',
+  traceId: 'trace-diff',
+};
+
+const lintResult: PolicyLintResult = {
+  policyPackId: 'policy-pack-001',
+  policyVersion: 1,
+  compiled: true,
+  totalIssues: 0,
+  errorCount: 0,
+  warningCount: 0,
+  infoCount: 0,
+  issues: [],
+  lintedAt: '2026-03-10T00:00:00Z',
+  traceId: 'trace-lint',
+};
+
+const gateResult: PromotionGateResult = {
+  policyPackId: 'policy-pack-001',
+  policyVersion: 2,
+  targetEnvironment: 'production',
+  overallStatus: 'ready',
+  checks: [],
+  allRequiredPassed: true,
+  blockingIssues: 0,
+  warnings: 0,
+  canOverride: false,
+  computedAt: '2026-03-10T00:00:00Z',
+  traceId: 'trace-gate',
+};
+
+describe('policy simulation direct-route defaults', () => {
+  afterEach(() => {
+    TestBed.resetTestingModule();
+  });
+
+  it('hydrates coverage with defaulted inputs on first render', async () => {
+    const api = createPolicySimulationApiMock();
+    api.getCoverage.and.returnValue(of(coverageResult));
+
+    await TestBed.configureTestingModule({
+      imports: [CoverageFixtureComponent],
+      providers: [{ provide: POLICY_SIMULATION_API, useValue: api }],
+    }).compileComponents();
+
+    const fixture = TestBed.createComponent(CoverageFixtureComponent);
+    const component = fixture.componentInstance;
+
+    (component as any).policyPackId = '   ';
+    (component as any).policyVersion = '0';
+
+    fixture.detectChanges();
+    await fixture.whenStable();
+
+    expect(component.policyPackId).toBe('policy-pack-001');
+    expect(component.policyVersion).toBeUndefined();
+    expect(api.getCoverage).toHaveBeenCalledWith({
+      tenantId: 'default',
+      policyPackId: 'policy-pack-001',
+      policyVersion: undefined,
+    });
+    expect(component.result()).toEqual(coverageResult);
+  });
+
+  it('restores diff fallbacks before loading a direct route comparison', async () => {
+    const api = createPolicySimulationApiMock();
+    api.getDiff.and.returnValue(of(diffResult));
+
+    await TestBed.configureTestingModule({
+      imports: [PolicyDiffViewerComponent],
+      providers: [{ provide: POLICY_SIMULATION_API, useValue: api }],
+    }).compileComponents();
+
+    const fixture = TestBed.createComponent(PolicyDiffViewerComponent);
+    const component = fixture.componentInstance;
+
+    (component as any).policyPackId = undefined;
+    (component as any).fromVersion = '';
+    (component as any).toVersion = '0';
+
+    component.ngOnChanges({
+      policyPackId: new SimpleChange('custom-pack', undefined, false),
+      fromVersion: new SimpleChange(5, '' as unknown as number, false),
+      toVersion: new SimpleChange(6, '0' as unknown as number, false),
+    });
+
+    expect(component.policyPackId).toBe('policy-pack-001');
+    expect(component.fromVersion).toBe(1);
+    expect(component.toVersion).toBe(2);
+    expect(api.getDiff).toHaveBeenCalledWith('policy-pack-001', 1, 2);
+    expect(component.result()).toEqual(diffResult);
+  });
+
+  it('normalizes lint inputs before issuing the live lint request', async () => {
+    const api = createPolicySimulationApiMock();
+    api.lintPolicy.and.returnValue(of(lintResult));
+
+    await TestBed.configureTestingModule({
+      imports: [PolicyLintComponent],
+      providers: [{ provide: POLICY_SIMULATION_API, useValue: api }],
+    }).compileComponents();
+
+    const fixture = TestBed.createComponent(PolicyLintComponent);
+    const component = fixture.componentInstance;
+
+    (component as any).policyPackId = undefined;
+    (component as any).policyVersion = '0';
+
+    component.runLint();
+
+    expect(component.policyPackId).toBe('policy-pack-001');
+    expect(component.policyVersion).toBeUndefined();
+    expect(api.lintPolicy).toHaveBeenCalledWith('policy-pack-001', undefined);
+    expect(component.result()).toEqual(lintResult);
+  });
+
+  it('normalizes promotion-gate defaults before checking the gate', async () => {
+    const api = createPolicySimulationApiMock();
+    api.checkPromotionGate.and.returnValue(of(gateResult));
+    api.overridePromotionGate.and.returnValue(of(gateResult));
+
+    await TestBed.configureTestingModule({
+      imports: [PromotionGateComponent],
+      providers: [
+        provideRouter([]),
+        { provide: POLICY_SIMULATION_API, useValue: api },
+      ],
+    }).compileComponents();
+
+    const fixture = TestBed.createComponent(PromotionGateComponent);
+    const component = fixture.componentInstance;
+
+    (component as any).policyPackId = undefined;
+    (component as any).policyVersion = '0';
+    (component as any).targetEnvironment = '   ';
+
+    component.checkGate();
+
+    expect(component.policyPackId).toBe('policy-pack-001');
+    expect(component.policyVersion).toBe(2);
+    expect(component.targetEnvironment).toBe('production');
+    expect(api.checkPromotionGate).toHaveBeenCalledWith({
+      tenantId: 'default',
+      policyPackId: 'policy-pack-001',
+      policyVersion: 2,
+      targetEnvironment: 'production',
+    });
+    expect(component.result()).toEqual(gateResult);
+  });
+});
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.spec.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.spec.ts
index 457baecb3..9686913a4 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.spec.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.spec.ts
@@ -47,7 +47,7 @@ describe('PromotionGateComponent', () => {
         docsUrl: 'https://docs.example.com/shadow-mode',
       },
     ],
-    checkedAt: new Date().toISOString(),
+    computedAt: new Date().toISOString(),
     traceId: 'trace-123',
   };
 
@@ -79,9 +79,9 @@ describe('PromotionGateComponent', () => {
     mockApi = jasmine.createSpyObj('PolicySimulationApi', [
       'checkPromotionGate',
       'overridePromotionGate',
-    ]);
+    ]) as jasmine.SpyObj<PolicySimulationApi>;
     mockApi.checkPromotionGate.and.returnValue(of(mockGateResult));
-    mockApi.overridePromotionGate.and.returnValue(of({ ...mockBlockedResult, overallStatus: 'overridden' }));
+    mockApi.overridePromotionGate.and.returnValue(of({ ...mockBlockedResult, overallStatus: 'ready' }));
 
     await TestBed.configureTestingModule({
       imports: [PromotionGateComponent, ReactiveFormsModule],
@@ -121,16 +121,31 @@ describe('PromotionGateComponent', () => {
       expect(component.policyPackId).toBe('custom-pack');
     });
 
+    it('should restore the default policy pack id when routing supplies undefined', () => {
+      (component as any).policyPackId = undefined;
+      expect(component.policyPackId).toBe('policy-pack-001');
+    });
+
     it('should accept policyVersion input', () => {
       component.policyVersion = 5;
       expect(component.policyVersion).toBe(5);
     });
 
+    it('should restore the default policy version when routing supplies an unusable value', () => {
+      (component as any).policyVersion = '0';
+      expect(component.policyVersion).toBe(2);
+    });
+
     it('should accept targetEnvironment input', () => {
       component.targetEnvironment = 'staging';
       expect(component.targetEnvironment).toBe('staging');
     });
 
+    it('should restore the default target environment when routing supplies an empty value', () => {
+      (component as any).targetEnvironment = '   ';
+      expect(component.targetEnvironment).toBe('production');
+    });
+
     it('should clear result on input change', fakeAsync(() => {
       component['result'].set(mockGateResult);
       component.ngOnChanges({
diff --git a/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.ts b/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.ts
index 870c11aa5..20b2cbc86 100644
--- a/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.ts
+++ b/src/Web/StellaOps.Web/src/app/features/policy-simulation/promotion-gate.component.ts
@@ -14,6 +14,14 @@ import {
   PromotionGateCheck,
   GateCheckStatus,
 } from '../../core/api/policy-simulation.models';
+import {
+  DEFAULT_POLICY_PACK_ID,
+  DEFAULT_POLICY_VERSION,
+  DEFAULT_TARGET_ENVIRONMENT,
+  normalizePolicyPackId,
+  normalizePolicyVersion,
+  normalizeTargetEnvironment,
+} from './policy-simulation-defaults';
 
 /**
  * Promotion gate component for checklist enforcement before production apply.
@@ -629,10 +637,36 @@ export class PromotionGateComponent implements OnChanges {
   private readonly api = inject(POLICY_SIMULATION_API);
   private readonly fb = inject(FormBuilder);
   private readonly router = inject(Router);
+  private _policyPackId = DEFAULT_POLICY_PACK_ID;
+  private _policyVersion = DEFAULT_POLICY_VERSION;
+  private _targetEnvironment = DEFAULT_TARGET_ENVIRONMENT;
 
-  @Input() policyPackId = 'policy-pack-001';
-  @Input() policyVersion = 2;
-  @Input() targetEnvironment = 'production';
+  @Input()
+  set policyPackId(value: string | null | undefined) {
+    this._policyPackId = normalizePolicyPackId(value);
+  }
+
+  get policyPackId(): string {
+    return this._policyPackId;
+  }
+
+  @Input()
+  set policyVersion(value: number | string | null | undefined) {
+    this._policyVersion = normalizePolicyVersion(value, DEFAULT_POLICY_VERSION);
+  }
+
+  get policyVersion(): number {
+    return this._policyVersion;
+  }
+
+  @Input()
+  set targetEnvironment(value: string | null | undefined) {
+    this._targetEnvironment = normalizeTargetEnvironment(value);
+  }
+
+  get targetEnvironment(): string {
+    return this._targetEnvironment;
+  }
 
   readonly loading = signal(false);
   readonly result = signal<PromotionGateResult | undefined>(undefined);
diff --git a/src/Web/StellaOps.Web/tsconfig.spec.features.json b/src/Web/StellaOps.Web/tsconfig.spec.features.json
index 281130520..36d26f90b 100644
--- a/src/Web/StellaOps.Web/tsconfig.spec.features.json
+++ b/src/Web/StellaOps.Web/tsconfig.spec.features.json
@@ -9,6 +9,8 @@
     "src/app/features/deploy-diff/components/deploy-diff-panel/deploy-diff-panel.component.spec.ts",
     "src/app/features/deploy-diff/pages/deploy-diff.page.spec.ts",
     "src/app/features/deploy-diff/services/deploy-diff.service.spec.ts",
+    "src/app/features/policy-simulation/policy-simulation-direct-route-defaults.spec.ts",
+    "src/app/features/policy-simulation/policy-simulation-defaults.spec.ts",
     "src/app/features/policy-simulation/simulation-dashboard.component.spec.ts",
     "src/app/features/registry-admin/registry-admin.component.spec.ts",
     "src/app/features/evidence-thread/__tests__/evidence-thread-view.component.spec.ts"