[AZ-701] Fix Jetson e2e harness infrastructure blockers

- gtsam_isam2_estimator: shim for gtsam>=4.3a0 aarch64 pre-release
  where IncrementalFixedLagSmoother/FixedLagSmootherKeyTimestampMap
  moved from gtsam_unstable to gtsam
- inference_factory: eager import of c7_inference package so
  register_component_block runs before config.components is read
- docker-compose.test.jetson.yml: remove companion and
  operator-orchestrator (not needed by replay CLI tests and crash
  in test env due to AZ-618 live-mode deps); add db-migrate and
  tile-init setup-profile services for Alembic migrations and FAISS
  fixture provisioning; update e2e-runner depends_on to db only
- scripts/mk_test_faiss_fixture.py: generate minimal HNSW32 FAISS
  descriptor index into the tile-data volume for the test harness

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

scripts/mk_test_faiss_fixture.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""Create a minimal valid FAISS HNSW32 + IndexIDMap2 fixture for the test harness.
+
+Used by the `tile-init` init service in docker-compose.test.jetson.yml.
+Writes three files to /var/lib/gps-denied/tiles/:
+  descriptor.index          — empty HNSW32 dim=512 binary
+  descriptor.index.sha256   — sha256 sidecar (matches FaissDescriptorIndex._load)
+  descriptor.index.meta.json — metadata (descriptor_dim, hnsw_params.metric, ...)
+
+Running this twice is idempotent (overwrites the previous fixture).
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+from datetime import datetime, timezone
+from pathlib import Path
+
+import faiss  # type: ignore[import-untyped]
+
+DESCRIPTOR_DIM = 512
+HNSW_M = 32
+
+root = Path("/var/lib/gps-denied/tiles")
+root.mkdir(parents=True, exist_ok=True)
+
+inner = faiss.IndexHNSWFlat(DESCRIPTOR_DIM, HNSW_M, faiss.METRIC_INNER_PRODUCT)
+index = faiss.IndexIDMap2(inner)
+
+idx_path = root / "descriptor.index"
+faiss.write_index(index, str(idx_path))
+idx_bytes = idx_path.read_bytes()
+sha256 = hashlib.sha256(idx_bytes).hexdigest()
+
+(idx_path.parent / (idx_path.name + ".sha256")).write_text(sha256, encoding="ascii")
+
+meta = {
+    "descriptor_dim": DESCRIPTOR_DIM,
+    "n_vectors": 0,
+    "backbone_label": "ultra_vpr",
+    "backbone_sha256_hex": "0" * 64,
+    "built_at": datetime.now(timezone.utc).isoformat(),
+    "hnsw_params": {
+        "m": HNSW_M,
+        "ef_construction": 40,
+        "ef_search": 16,
+        "metric": "INNER_PRODUCT",
+    },
+    "sidecar_sha256_hex": sha256,
+    "file_path": str(idx_path),
+    "id_mapping": [],
+}
+(idx_path.parent / (idx_path.name + ".meta.json")).write_text(
+    json.dumps(meta, sort_keys=True, indent=2), encoding="utf-8"
+)
+
+print(
+    f"[tile-init] OK: empty HNSW32 dim={DESCRIPTOR_DIM} index "
+    f"at {idx_path}  sha256={sha256[:16]}..."
+)