fix(active-content,conformance): cite line numbers per commit — they do not resolve at the pin

pattern_id_space.verified cited active_content.py:337-369 and :309. Those resolve at
de09711, where the check was run; this file's provenance pins 0bf0729, where the same
six call sites are at 316-348 and the emitter at 288. The 23-line scan-cap insert
shifts everything below it by 21, so a reader following the pin landed on the wrong
lines - and on lines that look plausible rather than obviously wrong.

Same defect class as the at_commit_note corrected before the first commit, one layer
deeper: a measured fact stated without the coordinate it is true in. Both commits'
numbers are now given, plus the symbol names, which are stable across the diff and
are what a reader should actually match on.

omitted_payloads[0].source gets the same treatment - coverage.py:484 is de09711-
relative, and the structural description now carries the load instead.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CVouC9nsfrfV5jRSejxbvQ

conformance/manifest.json

@@ -27,7 +27,7 @@
   },
   "omitted_payloads": [
     {
-      "source": "llm-ingestion-pipeline-security src/llm_ingestion_guard/coverage.py:484",
+      "source": "llm-ingestion-pipeline-security src/llm_ingestion_guard/coverage.py:484, at commit de09711 (line numbers are commit-relative; the structure is the fifth `_scan_case` of `_build_cases()`'s `active` group)",
       "described_as": "opaque (base64) path segment",
       "expected_label": "active:markdown-image",
       "reason": "Its in-scope finding set is `[active:markdown-image]` — identical, measured, to the case built from coverage.py:476. The only thing that distinguishes it is `entropy:base64-blob`, and this repository publishes no entropy table, so the difference falls outside every declared scope. A second case could not have failed in any way the first does not, and the case-id derivation has no room for it (see `case_id_derivation.one_case_per_pattern_id`).",