feat(desktop): add nest commit identity guidance with human sign-off

desktop/src-tauri/src/managed_agents/nest.rs

@@ -41,7 +41,7 @@ const SPROUT_CLI_SKILL_MD: &str = include_str!("nest_skill.md");
 /// Template content version for AGENTS.md static content (above managed markers).
 /// Bump this when changing `nest_agents.md` to trigger refresh on existing installs.
 /// Version 1 is implicitly "before this mechanism existed" (no version file).
-const NEST_AGENTS_VERSION: u32 = 3;
+const NEST_AGENTS_VERSION: u32 = 4;
 
 /// Template content version for SKILL.md.
 /// Bump this when changing `nest_skill.md` to trigger refresh on existing installs.

desktop/src-tauri/src/managed_agents/nest_agents.md

@@ -42,9 +42,18 @@ created: 2026-01-15
 - **Cite sources** — no claim without a path, link, or reference
 - **Don't overwrite** — append or create new files; don't silently clobber existing work
 - **`.scratch/` is disposable** — don't rely on it across sessions
-- **Never push without approval** — do not `git push` to any remote
 - **Stay on task** — only stage files relevant to your current work
 
+## Git Commit Identity
+
+The human operator signs off for accountability.
+
+- **Human sign-off (required):** every commit MUST include a `Signed-off-by` trailer for the human operator who is responsible for the agent's work. Add via `git commit --trailer "Signed-off-by: Human Name <human@email>"`. One blank line must separate trailers from the commit body.
+- **Human credit (`Co-authored-by`):** every commit MUST also include a `Co-authored-by` trailer for the same human operator, with identical name and email to the `Signed-off-by` line. GitHub parses `Co-authored-by` for contribution-graph credit; `Signed-off-by` alone does not grant it. Add via `git commit --trailer "Co-authored-by: Human Name <human@email>"`. Place `Co-authored-by` before `Signed-off-by` in the trailer block.
+- **Discovering the human's identity:** read `git config user.name` and `git config user.email` from the working repository. These reflect the human operator's configured identity for that repo (which may differ from their global config). Use these exact values for both trailers. Do NOT hardcode, guess, or prompt for the email — the repo config is the source of truth. If `git config user.email` returns empty, STOP and ask the human operator for their name and email before committing.
+- **Signing:** if the agent has a registered signing key, sign commits. If not, commits will land unverified — this is acceptable until agent SSH keys are provisioned. Do NOT use the human's signing key.
+- **Verify before pushing:** `git log -1` should show the human's `Signed-off-by` trailer.
+
 <!-- BEGIN SPROUT MANAGED — regenerated automatically, do not edit below -->
 ## Active Agents