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/overleaf-with-claude-exportscontroller-3980b9/fixed.mjs

@@ -1,4 +1,4 @@
-// Provenance: ZUENS2020/overleaf-with-claude  (fixed).
+// Provenance: ZUENS2020/overleaf-with-claude exportProject (fixed).
 // repo: ZUENS2020/overleaf-with-claude
 // commit: 3980b9e5806defb63e45ae2696e6c1899f3a8431
 // parent: 5a886aa9fb9fe4e2203f3cb1d62c91f4be0525ed
@@ -9,8 +9,9 @@
 // relpath: services/web/app/src/Features/Exports/ExportsController.mjs
 // provenance: agent
 // mechanism: identity_from_request_body
+// upstream_start: 1
 
-import { expressify } from '@overleaf/promise-utils'
+from '@overleaf/promise-utils'
 import SessionManager from '../Authentication/SessionManager.mjs'
 import logger from '@overleaf/logger'
 import OError from '@overleaf/o-error'
@@ -80,3 +81,5 @@ async function exportProject(req, res, next) {
     throw err
   }
 }
+
+exportProject: expressify(exportProject),