[AZ-231] Add anchor verification gates

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/02_tasks/done/AZ-231_anchor_verification_matching.md

@@ -0,0 +1,88 @@
+# Anchor Verification Matching And Geometry Gates
+
+**Task**: AZ-231_anchor_verification_matching
+**Name**: Anchor Verification Matching And Geometry Gates
+**Description**: Verify retrieved candidates with ALIKED/DISK + LightGlue and geometric safety gates.
+**Complexity**: 5 points
+**Dependencies**: AZ-223_camera_ingest_calibration, AZ-225_tile_manager_cache_manifest, AZ-230_satellite_service_vpr_retrieval
+**Component**: Anchor Verification
+**Tracker**: AZ-231
+**Epic**: AZ-215
+
+## Problem
+
+VPR candidates are not trusted fixes; they require local feature matching, RANSAC geometry, provenance checks, and measurable rejection evidence.
+
+## Outcome
+
+- Anchor candidates are accepted or rejected with MRE, inlier count, homography, freshness/provenance, and reason metadata.
+- Matcher profiles can be benchmarked without making learned matching a per-frame VIO hot path.
+
+## Scope
+
+### Included
+- ALIKED/DISK + LightGlue matching profile behavior.
+- SIFT/ORB baseline profile.
+- OpenCV RANSAC/USAC geometry checks.
+- Anchor decision output and rejection reasons.
+
+### Excluded
+- VPR retrieval ranking.
+- Safety wrapper anchor fusion.
+
+## Dependencies
+
+### Document Dependencies
+- `_docs/02_document/contracts/shared/runtime_contracts.md`
+- `_docs/02_document/contracts/shared/geometry_time_sync.md`
+- `_docs/02_document/contracts/shared/config_errors_telemetry.md`
+
+## Acceptance Criteria
+
+**AC-1: Candidate verification emits evidence**
+Given retrieved candidates and a usable frame
+When verification runs
+Then each result includes acceptance state, MRE, inlier count, and rejection/acceptance reason.
+
+**AC-2: Unsafe candidates are rejected**
+Given low inliers, high MRE, stale provenance, or geometry failure
+When verification runs
+Then no accepted anchor decision is emitted for that candidate.
+
+**AC-3: Matcher benchmark is reportable**
+Given configured matcher profiles
+When benchmark runs
+Then profile runtime and quality metrics are reported.
+
+## Non-Functional Requirements
+
+**Performance**
+- Learned matching is trigger-based and profiled separately from BASALT.
+
+**Reliability**
+- SuperPoint is excluded from production unless legal approval exists.
+
+## Unit Tests
+
+| AC Ref | What to Test | Required Outcome |
+|--------|--------------|------------------|
+| AC-1 | Valid matching fixture | Evidence fields present |
+| AC-2 | Bad geometry fixture | Rejected decision |
+| AC-3 | Benchmark profiles | Metrics emitted |
+
+## Blackbox Tests
+
+| AC Ref | Initial Data/Conditions | What to Test | Expected Behavior | NFR References |
+|--------|-------------------------|--------------|-------------------|----------------|
+| AC-1 | Aerial/cache fixture | Anchor verification path | Accepted anchors meet MRE/inlier gates | Performance |
+
+## Constraints
+
+- ALIKED/DISK + LightGlue supplies correspondences, not full VIO.
+- Anchor verification does not decide final safety fusion.
+
+## Risks & Mitigation
+
+**Risk 1: False anchor acceptance**
+- *Risk*: Cross-domain match looks plausible but is wrong.
+- *Mitigation*: Geometry, freshness, provenance, and downstream Mahalanobis gates.