[EHotwagner]

HighBarV3 cannot integrate its reviewed client upgrade because its default branch has no routine-eligibility producer. Its existing CI also falls outside the maintained first-install receiver qualification.

Add a receiver-specific first-install predicate for repository 1393546381 and unchanged master ci.yml. It authenticates classic/effective/inherited policy, preserves newly required checks, and requires the complete exact-head pull_request attempt-1 run, base/head association, Actions suite, ten jobs/checks and successful ordered technical steps. Repository and inherited organization variables determine conditional execution; a runner-variable update after the run refuses qualification. The pinned push-only reproducibility job remains skipped on PRs. The canonical five-file installation predicate and existing custody behavior remain unchanged.

Composition: this candidate is based on accepted archive merge 79f9fe8. The three reviewed executable/fixture payloads and their preimages match independently approved 5ec448cba0b0ca54dc2232acd57a5760d13a198a exactly; every other base leaf is unchanged except the current census source digest joined to the changed helper. The accepted archive merge has a disjoint path set and all its bytes are preserved. Original validation below is retained; final native required CI is pending.

The live V1 writer-census row is rehashed to the reviewed helper without changing its V2 delivery-boundary classification, mutation explanation, or historical GS2 evidence. The maintained structural validator first refused the stale digest and then passed after this scalar repair; the external/legacy producer-fence join also passes. This adds docs/coordination/v1-writer-census.json as the fourth changed path.

Validation:

• Full delivery fixture suite: Ran 276 tests in 11.626s / OK.
• Existing custody mutation controls: routine-delivery board mutate: 73/73 mutants killed.
• Routine eligibility workflow controls: bash tests/routine-eligibility/run.sh exited 0.
• Routine development/protected-operation route consistency: PASS.
• git diff --check: clean.
• Census structural check: 54 command roots: 20 always, 6 conditional, 28 never; 9 out-of-catalogue arms; 75 source identities; 345 tracked executables.

The new fixtures use inert native transport, temporary isolated Git repositories, fixed run/variable clocks (2026-11-01 and 2026-10-31), and exact public HighBar master workflow bytes from b57f11f290dc3239d894b0285ae272b6b21bc25d. Positive and causal negative cases cover the pure install, native policy/metadata denial or incompleteness, source/mode/unrelated-tree drift, job/check/step provenance, dynamically enabled or inherited runners, variable timing, required checks, fresh-policy drift and uncertain-effect readback. Local test execution was bounded to one CPU and 2 GiB. The first fixture assertion failure is retained locally; it expected ready in codeDelivery instead of the existing not-delivered value and was corrected.

This source merge leaves receiver installation and activation pending. The separate local receiver candidate adds exactly five canonical files and preserves every original receiver leaf, including ci.yml. Actual receiver candidate CI, maintained first-install merge/readback and genuine normal eligibility on client PR17 are still required under #5257. The existing client run is not installation evidence: a read-only probe correctly refused its changed ci.yml. No branch policy, permissions or client PR changes are included.

Refs #5257