feat(metrics): Implement scan metrics repository and PostgreSQL integration

- Added IScanMetricsRepository interface for scan metrics persistence and retrieval.
- Implemented PostgresScanMetricsRepository for PostgreSQL database interactions, including methods for saving and retrieving scan metrics and execution phases.
- Introduced methods for obtaining TTE statistics and recent scans for tenants.
- Implemented deletion of old metrics for retention purposes.

test(tests): Add SCA Failure Catalogue tests for FC6-FC10

- Created ScaCatalogueDeterminismTests to validate determinism properties of SCA Failure Catalogue fixtures.
- Developed ScaFailureCatalogueTests to ensure correct handling of specific failure modes in the scanner.
- Included tests for manifest validation, file existence, and expected findings across multiple failure cases.

feat(telemetry): Integrate scan completion metrics into the pipeline

- Introduced IScanCompletionMetricsIntegration interface and ScanCompletionMetricsIntegration class to record metrics upon scan completion.
- Implemented proof coverage and TTE metrics recording with logging for scan completion summaries.

docs/db/RULES.md

@@ -334,6 +334,50 @@ cmd.Parameters.AddWithValue("config", json);
 var json = Newtonsoft.Json.JsonConvert.SerializeObject(obj);
 ```
 
+### 5.3.1 Generated Columns for JSONB Hot Keys
+
+**RULE:** Frequently-queried JSONB fields (>10% of queries) SHOULD be extracted as generated columns.
+
+**When to use generated columns:**
+- Field is used in WHERE clauses frequently
+- Field is used in JOIN conditions
+- Field is used in GROUP BY or ORDER BY
+- Query planner needs cardinality statistics
+
+```sql
+-- ✓ CORRECT: Generated column for hot JSONB field
+ALTER TABLE scheduler.runs
+ADD COLUMN finding_count INT GENERATED ALWAYS AS ((stats->>'findingCount')::int) STORED;
+
+CREATE INDEX idx_runs_finding_count ON scheduler.runs(tenant_id, finding_count);
+```
+
+**RULE:** Generated column names MUST follow snake_case convention matching the JSON path.
+
+```sql
+-- ✓ CORRECT naming
+doc->>'bomFormat'      → bom_format
+stats->>'findingCount' → finding_count
+raw->>'schemaVersion'  → schema_version
+
+-- ✗ INCORRECT naming
+doc->>'bomFormat' → bomFormat, format, bf
+```
+
+**RULE:** Generated columns MUST be added with concurrent index creation in production.
+
+```sql
+-- ✓ CORRECT: Non-blocking migration
+ALTER TABLE scheduler.runs ADD COLUMN finding_count INT GENERATED ALWAYS AS (...) STORED;
+CREATE INDEX CONCURRENTLY idx_runs_finding_count ON scheduler.runs(finding_count);
+ANALYZE scheduler.runs;
+
+-- ✗ INCORRECT: Blocking migration
+CREATE INDEX idx_runs_finding_count ON scheduler.runs(finding_count); -- Blocks table
+```
+
+**Reference:** See `SPECIFICATION.md` Section 6.4 for detailed guidelines.
+
 ### 5.4 Null Handling
 
 **RULE:** Nullable values MUST use `DBNull.Value` when null.