feat(learning-harness): absence rows travel with their registration

Eight of the ten vendored access-control rows had no named handler at all,
so every one of them would have scored `missing_context` forever rather
than as a detector miss. After the re-harvest nine are named and the tenth
states its reason.

The handler-context mode now carries the class its framework registers,
multi-line decorators, and commented-out guards -- `#@token_required`
above a ThreatByte handler is the entire bug. Where the registration lives
in another document (connexion's `operationId`, an express router), a
recipe names `context = [...]`, the harvester writes that stanza per side,
and the pair materializes both files at their repository-relative paths so
the entry-point mapper sees the layout the project has. `harvest_recipe`
fetches every blob before the first write and the driver takes `--report`,
so a failed fetch leaves a reviewed excerpt exactly as it was.

Two defects the re-harvest exposed: `.mjs` was not a known suffix, so the
one pair vendored as an ES module had no file target at all; and
`_python_route_access` matched auth words inside decorator prose, reading
`@ns.doc(description='... without proper authorization checks')` as a
guard. Recorded in the hygiene artifact: nine of the ten duplicate groups
sit on both sides of the split, which the repository-level split cannot
see.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG

benchmarks/pairs/agent-vfc/workers-research-utils-209444/fixed.ts

@@ -5,7 +5,7 @@
 // commit_url: https://github.com/G4brym/workers-research/commit/209444eb61cc564c2d6b43267256f85fe3e5e30e
 // cve: 
 // license: MIT
-// function: normalizeDomain
+// function: getGoogleProvider
 // relpath: src/utils.ts
 // provenance: agent
 // mechanism: source_reaches_sink

benchmarks/pairs/agent-vfc/workers-research-utils-209444/vuln.ts

@@ -5,7 +5,7 @@
 // commit_url: https://github.com/G4brym/workers-research/commit/209444eb61cc564c2d6b43267256f85fe3e5e30e
 // cve: 
 // license: MIT
-// function: normalizeDomain
+// function: getGoogleProvider
 // relpath: src/utils.ts
 // provenance: agent
 // mechanism: source_reaches_sink