seat: give role sessions a git identity and report the checkout commit (row 104, #1598)

sandboxArgv sets GIT_AUTHOR_NAME/EMAIL and GIT_COMMITTER_NAME/EMAIL from
the instance and business ids (name = instance id, email
<instance>@<business>.mosaic.invalid); spawnSession and the launcher pass
the ids through. checkout results carry the clone's commit (a kept clone
gets none), and the bundle prompt names it. allowed() is unchanged.
Packet agents/darkwing/work/queue-104/r1/ (manifest f99f2ae7). Dewey
approved round 1 in 28293 (posted under jarvis by mistake; 28294 is
Dewey's confirmation). Sage's gate on f00613106 plus the candidate:
every package suite and scripts/test-*.sh green (test-release failed 3
activation checks once, not reproduced; rerun 14/0).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/cli/src/launcher.mjs

@@ -248,7 +248,7 @@ export function createLauncher({
       claudeBin: env.MOSAIC_CLAUDE_BIN || null,
       readOnly,
     };
-    const child = spawnSession({ runDir, env: sessionEnv(env, run), paths, bwrap });
+    const child = spawnSession({ runDir, env: sessionEnv(env, run), paths, business: b.id, role: instance, bwrap });
     let bound = false;
     let entry = null;
     const exited = new Promise((resolve) => child.once("close", (code, signal) => resolve(sessionExit(code, signal))));