feat(routing): implement ActivityKnowledgeBase with loader

Task 1.2 & 1.3 COMPLETE ✅

Core knowledge base infrastructure:
- activity_knowledge_base.json: Catalog of 8 activities with metadata
  - CloneRepoActivity: Clone Git repo (stable, 1 retry)
  - AnalyzeCodeActivity: AST analysis (flaky, 3 retries)
  - SecurityScanActivity: SAST scanning (2 retries)
  - GenerateReportActivity: Report generation (1 retry)
  - DeploymentPreCheckActivity: Pre-deployment validation (flaky, 2 retries)
  - NotifyStatusActivity: Slack/email notifications (flaky, 3 retries)
  - ApproveWorkflowActivity: Human approval (120m timeout)
  - ArchiveResultsActivity: Cloud storage archival (flaky, 2 retries)

- knowledge_base.go: KnowledgeBase loader with methods:
  - LoadKnowledgeBase(path) - Load from JSON file
  - LoadKnowledgeBaseFromDefaultPath() - Auto-discover file
  - GetActivity(name) - Lookup single activity
  - GetActivityNames() - List all activity names
  - HasActivity(name) - Check existence
  - GetTimeoutForActivity(name) - Get timeout from KB
  - GetRetryPolicyForActivity(name) - Get retry config
  - IsFlaky(name) - Check if flaky
  - GetDependencies(name) - Get activity dependencies
  - ListActivitiesByCategory(category) - Filter by category
  - Validate() - Check for circular dependencies
  - PrintSummary() - Human-readable summary

- knowledge_base_test.go: 14 unit tests
  - Test loading, lookup, filtering, dependencies
  - Test timeout/retry extraction
  - Test validation logic
  - All tests PASS ✅ (22/22 total)

Acceptance criteria met:
✅ Knowledge base loads successfully
✅ All 8 activities properly defined
✅ Flaky/stable flags correctly set
✅ Dependencies validate with no cycles
✅ Timeout/retry extraction works
✅ Unit tests pass (14/14 KB tests)
✅ Ready for validator (Task 1.4)

Effort: 5 hours (estimated 3+2)
Files: activity_knowledge_base.json (10.3KB)
       knowledge_base.go (246 lines)
       knowledge_base_test.go (324 lines)

k8s/git-commit.yaml

@@ -9,6 +9,6 @@ metadata:
     app.kubernetes.io/name: poimen
     app.kubernetes.io/component: orchestrator
 data:
-  GIT_COMMIT: "c5994df8"  # Updated automatically by CI/CD
+  GIT_COMMIT: "f03184ad"  # Updated automatically by CI/CD
   GIT_BRANCH: "main"
   DEPLOYMENT_DATE: "2026-08-31"