Evidence report: main's committed copy is stale since the move to the generated branch (L-levels read from Oct 12) #5206

Siblings: #4963 (moved the evidence report to the generated branch; this is the fallback copy it left behind).

Problem. Since #4963 / PR #5017, evidence-refresh.yml publishes the evidence report to the generated branch only. The committed copy on main (docs/language_status/evidence_report/) is now a fallback nobody refreshes: its last change is 2026-10-12 (#4923). Readers that open main's copy see old levels. README.md, docs/ci.md, definition_of_done.md, estate_intake.md, evidence_records.md, feature_inventory.md, .claude/agents/gitgalaxy-pr-worker.md and the blocker-slice / cics-command-slice skills all link or read it.

CardDemo alone reads L2 12 / L3 3 on main vs L2 3 / L3 13 live. The nightly run's own log says "no changes added to commit", which looks like a broken refresh but is the intended behaviour since #4963.

Change. One source of truth for the levels, wherever someone reads them:

• Replace main's docs/language_status/evidence_report/ with a stub README that names the generated branch (and how to read it: tests/tools/generated_branch.py show), or drop it and keep the readers' generated-first fallback working without it.
• Point README.md and the docs above at the generated copy, not main's.
• Agents/skills that read the report go through generated_branch.py show, as Remaining bot writers to main: move ground-truth history, evidence report, architecture brief to the generated branch #4963's acceptance says.
• A guard test: no doc on main links a file that only generated keeps current.

Acceptance: nothing on main shows evidence levels older than the latest nightly; evidence_report.py --check --live and the release gate still work; test_generated_branch.py allow list updated.