Expose checkout authority collisions in PortfolioTruth (#211)

* feat(portfolio): expose checkout authority collisions

* fix(portfolio): fail closed on discarded worktree changes

* fix(audit): suppress blocked pilot records

* fix(portfolio): prefer working checkout authority

* fix(automation): gate catalog seeds on checkout authority

* fix(portfolio): honor declared checkout authority

* fix(portfolio): observe excluded linked worktrees

* fix(portfolio): fail closed on unresolved declarations

* fix(portfolio): validate expanded checkout authority

* fix(portfolio): preserve unknown topology evidence

* Preserve external worktree authority evidence

* Redact external repository topology

* Fail closed on incomplete checkout topology

* Preserve canonical identity across worktrees

* Preserve canonical checkout policy

* fix: validate checkout authority consistently

* fix: preserve checkout identity and fail closed

Author: saagpatel

fixtures/contracts/portfolio-command-center-v1/manifest.json

@@ -24,7 +24,7 @@
   "portfolio_truth_schema_version": "0.11.0",
   "producer": {
     "artifact_path": "fixtures/contracts/portfolio-command-center-v1/portfolio-truth.json",
-    "artifact_sha256": "ba3000833f1cd9c89442948ebe51f7e405e7832333a69c6f7347fb2fbfae254a",
+    "artifact_sha256": "5b12c9851e43f82bcaf872f900539d5a5b67da9d405a7e73f7d3a20bfcdb9eae",
     "generator": "src.portfolio_truth_contract_fixture:build_contract_fixture",
     "manifest_path": "fixtures/contracts/portfolio-command-center-v1/manifest.json",
     "repository": "saagpatel/GithubRepoAuditor"

fixtures/contracts/portfolio-command-center-v1/portfolio-truth.json

@@ -64,7 +64,7 @@
   "derivation_policy_version": "portfolio_attention.v3",
   "exclusions": {
     "counts": {},
-    "policy_version": "workspace_discovery.v2"
+    "policy_version": "workspace_discovery.v3"
   },
   "generated_at": "2026-08-01T00:00:00+00:00",
   "inputs": {
@@ -1632,6 +1632,15 @@
     },
     "catalog_errors": [],
     "catalog_warnings": [],
+    "checkout_collisions": {
+      "ambiguous_group_count": 0,
+      "discarded_checkout_count": 0,
+      "full_clone_group_count": 0,
+      "group_count": 0,
+      "groups": [],
+      "schema_version": "CheckoutCollisionSummaryV1",
+      "state": "observed"
+    },
     "context_quality_counts": {
       "boilerplate": 1,
       "full": 1,