feat(discord): git verbs for the Discord Sage on the shared-signals root, seat identity through a package credential helper, vault record protocol (#1509)

Row 24. A writable root that is a git work tree may carry a git object in
the binding; the seat then has git_status, git_commit (explicit paths, seat
author, Requested-by trailer from the envelope requester, push at once per
D6), git_pull (ff-only) and git_push (one branch, never force), plus
reserve_id and per-write clone locks under protocol vault. Git children run
with no host config and one credential helper, bin/git-credential.mjs,
reading the 0600 seat token file named in the binding; the fleet helper
serves only the Gitea hosts. Suite 58/58, node 143. rev-code-02 APPROVED
round 1 (#1509 comment 26375, tree 82ab962f).

Co-Authored-By: Claude Fable 5.1 <[email protected]>

BUILD-LOG.md

@@ -2508,3 +2508,48 @@ and pi environment verified; Jason's first web turn worked. Records of the
 live setup live in the sage seat evidence directory, never in the repo.
 Follow-ups: a failed turn record should carry its partial tool calls; row
 24 (git verbs) is next.
+
+## 2026-09-18 — Discord git verbs for the shared-signals root (#1509, QUEUE row 24)
+
+Before: a write from Discord landed in Jason's clone and waited for him to
+commit it from the terminal. After: a writable root that is a git work
+tree may carry a `git` object in the binding, and the Discord Sage gets
+`git_status`, `git_commit`, `git_pull` and `git_push`, plus `reserve_id`
+under the shared-signals record protocol. Every verb is one `git` child
+with a fixed argument list inside the root, 60 s, output capped and
+masked. A commit stages exactly the paths named (one to fifty regular
+files under the root, no dot segment, no symlink), refuses when the index
+already holds someone's staged work, commits as `Sage <[email protected]>`
+with a `Requested-by:` trailer naming the Discord author's server name,
+and pushes at once (D6). A push that fails is still a commit and is said
+so; the next commit's push carries both. Pull is ff-only; push is one
+branch, never force. The guard refuses off the named branch, a detached
+head, a merge, rebase, cherry-pick, revert or bisect in progress, and any
+conflicted path. Under `protocol: "vault"`, writes take the clone lock
+for the path around the write, a commit runs `vault_lock.py check` and
+`validate_vault.py` first, and `reserve_id` appends the registry line.
+The requester comes from a new `requester="…"` field the connector writes
+into the envelope line and the extension reads on `before_agent_start`.
+
+Correction to the brief's draft (D5 mechanism): the fleet helper
+`git-credential-mosaic` serves only the two Gitea hosts and exits silently
+for github.com, and the host's global git config sends github.com to
+Jason's own `gh` login. Neither may act for Sage, so git children run with
+no host config at all (`GIT_CONFIG_GLOBAL=/dev/null`, `GIT_CONFIG_NOSYSTEM=1`,
+no askpass, no prompt) and one helper set through `GIT_CONFIG_COUNT`, the
+package's own `bin/git-credential.mjs`, which answers `get` over https
+from the 0600 token file the binding names. The connector checks that
+file's mode and never reads it; its path reaches git only for push, pull
+and reserve, through the environment. The identity D5 named is unchanged.
+
+Verification: `scripts/test-discord.sh` 58/58 and node tests 143 pass on
+the frozen bytes (`tests/git.test.mjs` against a local bare remote with
+stand-in vault scripts; a spy spawn asserts no argv holds the token or its
+path; the credential helper is driven as a child; the real pi is shown
+the verbs with a sandbox work tree and refuses `git` on a read-only
+root). Review: rev-code-02 round 1 pinned as #1509 comment 26374, tree
+82ab962f6a1baa0bb010f36da92645f80da67c13. rev-code-02 APPROVED round 1 on 2026-09-18T12:50:33Z (#1509 comment 26375).
+The binding change and the live check follow the local commit; the
+binding stays private. Jason's shared-signals clone holds his own
+uncommitted files; explicit-path staging leaves them alone, and Sage
+cannot commit while his index holds staged work.