[WP02 · SubStep 02.04] Remove macOS and runtime CI; retain Windows/Linux builds

[deku2026]

The current pipeline starts GUI/live Cloud checks on five hosts and requires their screenshots/smoke receipts before packaging. This change applies the accepted CI policy: compile/package Windows x64, Windows ARM64 and Linux x64; run platform-independent static/offline unit checks once; retain security and one publication-handoff identity/licence/integrity check.

• Remove macOS jobs, hosted UI/live smoke, implicit AOT execution during staging, smoke/screenshot candidate fields and duplicate aggregate artifact download/verification.
• Keep local macOS source support and explicit local smoke/loopback tests; the smoke tool rejects CI. Release inventories now require three archives and their checksums, with honest build-only evidence.
• Make Git hooks whitespace-only and update AGENTS, contributor/release/build-identity guidance and historical-plan supersession. Preserve all runtime application code, dependency pins, lockfiles and original provenance records.
• Preserve existing licence/source provenance checks and original records.

Validation: one cached managed Release build (0 warnings/errors), 97 offline unit tests, repository source/licence/provenance check and git diff --check passed locally. No local AOT build, GUI, loopback/live transport, public download, installation or runtime retest was performed. Applicable reduced hosted CI must pass before merge.

[deku2026]

Reviewed complete diff at a40c0e3 against origin/main, including workflow dependencies/release counts, hidden prepare/pack runtime coupling, candidate fixtures, hooks, active documentation and provenance successors. No blocking findings remain.

Removed six macOS/UI-runtime requirements across the matrix and reduced publication to the three actual Windows/Linux outputs. No packaged application is executed by the normal build/stage/pack/release path. Explicit smoke is local-only; loopback TransportTests are excluded from the offline hosted unit invocation. Candidate/source/licence integrity remains one publication-handoff check; Verify only checks job outcomes. Dependency pins, product runtime sources and old provenance records are unchanged.

Local managed build and 97 offline tests passed; source/licence/provenance/whitespace checks passed. No absent runtime/macOS result is represented as passed. Merge remains conditional on latest-head applicable CI success.