Adds an opt-in per-agent Gitea identity so a fleet agent can push/commit/open
PRs under its own token instead of the single shared account, giving
cryptographic author-!=-reviewer separation (Gate-16).
Resolution priority (both tools): MOSAIC_GIT_IDENTITY env > git config
mosaic.gitIdentity (per-worktree, persists on disk) > git-supplied username
(git-credential-mosaic only). If the resolved identity has a token file at
~/.config/mosaic/secrets/gitea-tokens/gitea-{usc,mosaicstack}-<id>.token, that
identity is used; otherwise both tools fall through to the existing
shared-account path unchanged, so this is a no-op on any host without
per-slot tokens configured.
- tools/git/git-credential-mosaic: new git credential helper (get verb).
- tools/git/detect-platform.sh: get_gitea_token() gains the same identity
resolution, prepended ahead of the existing shared-token logic, so API
tooling (pr-create.sh, issue-create.sh, ...) authors under the same
identity as git push/fetch.
- install.sh: explicit chmod +x for git-credential-mosaic (it ships without
a .sh suffix, so the existing *.sh glob does not cover it); tools/** is
already framework-owned so the file syncs automatically.
- tools/git/README.md: documents the feature, the one-time
`git config credential.helper` registration step (deliberately not
auto-wired — see README for why), and the PowerShell-parity decision
(detect-platform.ps1 authenticates via tea logins, not a raw-token
function, so there is nothing to port there).
- tools/git/test-git-credential-mosaic.sh,
tools/git/test-gitea-token-identity.sh: new regression harnesses (red
verified against the pre-patch code) covering identity-resolution
priority, per-host token path selection, and shared-account fallback.
Wired into package.json's test:framework-shell.
Upstreams Mos host-local tooling-patch kit (2026-07-23), Patches 1+2.
Closes#873
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
