feat(plane): repo-facts memory task (task 5)

plane/tasks/repo_facts.py computes, from source text only and without a
model or git, the product files of a workspace (tests, vendored trees,
node_modules, dist/build, minified bundles and dot-directories excluded via
the layout facts plus the model_sinks.py filter), the functions each file
declares (Python, PHP, JavaScript/TypeScript, Java, Go, Ruby declaration
patterns extended from sink_candidates.py) and, per candidate function, the
call sites in other product files with path, 1-based line and enclosing
function, capped at 40 and sorted (Requirement 5.1). Output is byte-identical
across runs over the same tree (Requirement 5.2).

Under the task contract the unit is one file: a row goes to units.jsonl as
each file finishes and a restart reuses the rows computed for the same
candidate set (Requirement 2.2); facts.json is assembled from the rows and
summary.json is written last, refusing `done` unless every unit finished.
The entrypoint reads OUSAST_WORKSPACE_DIR, OUSAST_OUTPUT_DIR and optional
OUSAST_INPUT_CANDIDATES only (Requirement 2.1) and exits 0 on done, 2 on
failed with the traceback recorded in summary.json.

tests/test_plane_repo_facts.py: a three-file tree with a tests/ file, a
vendored file, a node_modules bundle and a dot-directory; cross-file callers
with line and enclosing function, same-file and declaration lines excluded,
the 40 cap, byte-identical second run, resume that recomputes only the
missing unit, a crash that leaves `failed` with the unit counts and resumes
to `done`, and the declaration patterns per language.

The two new modules are registered as spec-owned in the module audit (their
importer, the runner, lands in task 3) and the audit manifest is regenerated.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

benchmarks/measurements/2026-09-08-module-audit.json

@@ -1,7 +1,7 @@
 {
-  "modules": 120,
+  "modules": 122,
   "counts": {
-    "load_bearing": 111,
+    "load_bearing": 113,
     "standalone_capability": 9
   },
   "orphaned": [],
@@ -401,6 +401,7 @@
         "model.specs",
         "model.taint",
         "plane.budget",
+        "plane.tasks.repo_facts",
         "preprocess",
         "push.assistance",
         "push.cache",
@@ -528,6 +529,7 @@
       "importers": [
         "model.partitions",
         "model.scan",
+        "plane.tasks.repo_facts",
         "preprocess",
         "push.runner"
       ]
@@ -661,6 +663,18 @@
       "reason": "ai-service-plane Req 2.3/2.4: metered chat client with usd and calls ceilings; task integration in tasks 3, 6",
       "importers": []
     },
+    {
+      "module": "plane.tasks",
+      "classification": "load_bearing",
+      "reason": "ai-service-plane Req 4.1: the task entrypoint package the runner imports by name; runner integration pending (task 3)",
+      "importers": []
+    },
+    {
+      "module": "plane.tasks.repo_facts",
+      "classification": "load_bearing",
+      "reason": "ai-service-plane Req 5.1/5.2: source-only functions and callers per file; runner integration pending",
+      "importers": []
+    },
     {
       "module": "policy",
       "classification": "load_bearing",
@@ -707,6 +721,7 @@
         "model.partitions",
         "model.scan",
         "pairs",
+        "plane.tasks.repo_facts",
         "push.runner",
         "rank",
         "regress.candidate",
@@ -1337,6 +1352,5 @@
         "cli"
       ]
     }
-  ],
-  "note": "Group 8: runner reaches recomputed versioned eligibility and its frozen scorer."
+  ]
 }