PR 20727: integrated headless server-service proof
Linux x64, Node24, Git2.43. Real GitManager and GitVcsDriver services; actual Git, local bare repositories, in-memory projection stores. Synthetic hosting response and setup callback. No UI or real hosting is claimed. Source is the integrated maintainer rebuild on merged-main branch batch-15b-20727; no production edits occurred between implementation checks and this run.

Before/after regression tests: the original eight new service cases fail behaviorally against main and pass after the guard/ref-remote change. GitManager full suite before review fix178/178 pass. One additional fork-layout row covers the confirmed review finding; all three fork rows pass after the fix. Driver168/169 pass; untouched rename preview case also fails against main with host Git2.43.

Round1 Sol finding independently reproduced before fix: local-path origin plus hosted fork match created the correct head, but reuse moved onto origin unrelated PR64 commit bb15fa306b794eac193e7b4a94dc5b534e80732c. The server probe exited1 on the exact-head assertion. Fix: with any hosted evidence and no matching base remote, numbered-ref remote is null; primary fallback is retained only without hosted evidence.

Final parent manual probe after fix:
20727-proof-final-r2.log
{"scenario":"unrelated-local","result":"refused","gitStateUnchanged":true,"setupCalls":0,"detail":"This project is not a checkout of fixture/base. Open the pull request from a project that is, or, if the repository was renamed, point this project's remote at its new name."}
{"scenario":"unrelated-worktree","result":"refused","gitStateUnchanged":true,"setupCalls":0,"detail":"This project is not a checkout of fixture/base. Open the pull request from a project that is, or, if the repository was renamed, point this project's remote at its new name."}
{"scenario":"fork-origin-base-named--base","result":"created","advertisedHead":"803f360b7409c34978f8b9c0a7a946c3ed33784c","actualHead":"803f360b7409c34978f8b9c0a7a946c3ed33784c","wrongOriginPrHead":"23b3f85ae7162fb0daa88f06c156512361925a7e"}
{"scenario":"reused-worktree","result":"refreshed","sameWorktree":true,"advertisedHead":"84d6ed0af12a86514fc8db2b535dd82e55b0c0ae","actualHead":"84d6ed0af12a86514fc8db2b535dd82e55b0c0ae","setupCalls":2}
20727-local-origin-after.log
{"scenario":"unrelated-local","result":"refused","gitStateUnchanged":true,"setupCalls":0,"detail":"This project is not a checkout of fixture/base. Open the pull request from a project that is, or, if the repository was renamed, point this project's remote at its new name."}
{"scenario":"unrelated-worktree","result":"refused","gitStateUnchanged":true,"setupCalls":0,"detail":"This project is not a checkout of fixture/base. Open the pull request from a project that is, or, if the repository was renamed, point this project's remote at its new name."}
{"scenario":"local-origin-hosted-fork","result":"created","advertisedHead":"0487489db5283a2fae0a956311155e5f3a48bfcb","actualHead":"0487489db5283a2fae0a956311155e5f3a48bfcb","wrongOriginPrHead":"753708e9811a8f70c1901c4fb19a1cb451c17256"}
{"scenario":"reused-worktree","result":"refreshed","sameWorktree":true,"advertisedHead":"ca732a895e0960dff38969495ef9707f1feae9cf","actualHead":"ca732a895e0960dff38969495ef9707f1feae9cf","setupCalls":2}

Both final probes exited0. Setup is a recorded boundary invocation, not execution of a user script. No UI, real hosting, native clients, macOS, Windows, Electron or relay/tunnel verification is claimed.