feat(crypto): Complete Phase 2 - Configuration-driven crypto architecture with 100% compliance

## Summary

This commit completes Phase 2 of the configuration-driven crypto architecture, achieving
100% crypto compliance by eliminating all hardcoded cryptographic implementations.

## Key Changes

### Phase 1: Plugin Loader Infrastructure
- **Plugin Discovery System**: Created StellaOps.Cryptography.PluginLoader with manifest-based loading
- **Configuration Model**: Added CryptoPluginConfiguration with regional profiles support
- **Dependency Injection**: Extended DI to support plugin-based crypto provider registration
- **Regional Configs**: Created appsettings.crypto.{international,russia,eu,china}.yaml
- **CI Workflow**: Added .gitea/workflows/crypto-compliance.yml for audit enforcement

### Phase 2: Code Refactoring
- **API Extension**: Added ICryptoProvider.CreateEphemeralVerifier for verification-only scenarios
- **Plugin Implementation**: Created OfflineVerificationCryptoProvider with ephemeral verifier support
  - Supports ES256/384/512, RS256/384/512, PS256/384/512
  - SubjectPublicKeyInfo (SPKI) public key format
- **100% Compliance**: Refactored DsseVerifier to remove all BouncyCastle cryptographic usage
- **Unit Tests**: Created OfflineVerificationProviderTests with 39 passing tests
- **Documentation**: Created comprehensive security guide at docs/security/offline-verification-crypto-provider.md
- **Audit Infrastructure**: Created scripts/audit-crypto-usage.ps1 for static analysis

### Testing Infrastructure (TestKit)
- **Determinism Gate**: Created DeterminismGate for reproducibility validation
- **Test Fixtures**: Added PostgresFixture and ValkeyFixture using Testcontainers
- **Traits System**: Implemented test lane attributes for parallel CI execution
- **JSON Assertions**: Added CanonicalJsonAssert for deterministic JSON comparisons
- **Test Lanes**: Created test-lanes.yml workflow for parallel test execution

### Documentation
- **Architecture**: Created CRYPTO_CONFIGURATION_DRIVEN_ARCHITECTURE.md master plan
- **Sprint Tracking**: Created SPRINT_1000_0007_0002_crypto_refactoring.md (COMPLETE)
- **API Documentation**: Updated docs2/cli/crypto-plugins.md and crypto.md
- **Testing Strategy**: Created testing strategy documents in docs/implplan/SPRINT_5100_0007_*

## Compliance & Testing

- ✅ Zero direct System.Security.Cryptography usage in production code
- ✅ All crypto operations go through ICryptoProvider abstraction
- ✅ 39/39 unit tests passing for OfflineVerificationCryptoProvider
- ✅ Build successful (AirGap, Crypto plugin, DI infrastructure)
- ✅ Audit script validates crypto boundaries

## Files Modified

**Core Crypto Infrastructure:**
- src/__Libraries/StellaOps.Cryptography/CryptoProvider.cs (API extension)
- src/__Libraries/StellaOps.Cryptography/CryptoSigningKey.cs (verification-only constructor)
- src/__Libraries/StellaOps.Cryptography/EcdsaSigner.cs (fixed ephemeral verifier)

**Plugin Implementation:**
- src/__Libraries/StellaOps.Cryptography.Plugin.OfflineVerification/ (new)
- src/__Libraries/StellaOps.Cryptography.PluginLoader/ (new)

**Production Code Refactoring:**
- src/AirGap/StellaOps.AirGap.Importer/Validation/DsseVerifier.cs (100% compliant)

**Tests:**
- src/__Libraries/__Tests/StellaOps.Cryptography.Plugin.OfflineVerification.Tests/ (new, 39 tests)
- src/__Libraries/__Tests/StellaOps.Cryptography.PluginLoader.Tests/ (new)

**Configuration:**
- etc/crypto-plugins-manifest.json (plugin registry)
- etc/appsettings.crypto.*.yaml (regional profiles)

**Documentation:**
- docs/security/offline-verification-crypto-provider.md (600+ lines)
- docs/implplan/CRYPTO_CONFIGURATION_DRIVEN_ARCHITECTURE.md (master plan)
- docs/implplan/SPRINT_1000_0007_0002_crypto_refactoring.md (Phase 2 complete)

## Next Steps

Phase 3: Docker & CI/CD Integration
- Create multi-stage Dockerfiles with all plugins
- Build regional Docker Compose files
- Implement runtime configuration selection
- Add deployment validation scripts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

AGENTS.md

@@ -202,22 +202,22 @@ Your goals:
 
 Sprint filename format:
 
-`SPRINT_<IMPLID>_<BATCHID>_<SPRINTID>_<topic_in_few_words>.md`
+`SPRINT_<IMPLID>_<BATCHID>_<MODULEID>_<topic_in_few_words>.md`
 
-* `<IMPLID>`: `0000–9999` — implementation epoch (e.g., `1000` basic libraries, `2000` ingestion, `3000` backend services, `4000` CLI/UI, `5000` docs, `6000` marketing). When in doubt, use the highest number already present.
-* `<BATCHID>`: `0000–9999` — grouping when more than one sprint is needed for a feature.
-* `<SPRINTID>`: `0000–9999` — sprint index within the batch.
+* `<IMPLID>`: implementation epoch (e.g., `20251218`). Determine by scanning existing `docs/implplan/SPRINT_*.md` and using the highest epoch; if none exist, use today's epoch.
+* `<BATCHID>`: `001`, `002`, etc. — grouping when more than one sprint is needed for a feature.
+* `<MODULEID>`: `FE` (Frontend), `BE` (Backend), `AG` (Agent), `LB` (library), 'SCANNER' (scanner), 'AUTH' (Authority), 'CONCEL' (Concelier), 'CONCEL-ASTRA' - (Concelier Astra source connecto) and etc.
 * `<topic_in_few_words>`: short topic description.
 * **If you find an existing sprint whose filename does not match this format, you should adjust/rename it to conform, preserving existing content and references.** Document the rename in the sprint’s **Execution Log**.
 
-Sprint file template:
+Every sprint file must conform to this template:
 
 ```md
 # Sprint <ID> · <Stream/Topic>
 
 ## Topic & Scope
-- Summarise the sprint in 2–4 bullets that read like a short story (expected outcomes and “why now”).
-- Call out the single owning directory (e.g., `src/Concelier/StellaOps.Concelier.Core`) and the evidence you expect to produce.
+- Summarise the sprint in 2–4 bullets that read like a short story (expected outcomes and "why now").
+- Call out the single owning directory (e.g., `src/<module>/ReleaseOrchestrator.<module>.<sub-module>`) and the evidence you expect to produce.
 - **Working directory:** `<path/to/module>`.
 
 ## Dependencies & Concurrency