docs: add git sync policy to AGENTS.md

AGENTS.md

@@ -85,6 +85,28 @@ THIS RULE APPLIES TO ALL MODELS (codex, deepseek, opencode).
    ```
 2. This automatically generates HANDOFF.md for the next session.
 3. If you cannot run the script, at minimum update the HANDOFF.md manually.
+4. AFTER saving the session, sync HANDOFF.md and updated files to the shared git repo.
+5. If the shared repo is available, include the sync commands in the save-session flow.
+
+### Git Sync Policy (Every Session)
+
+**Central repo**: `https://git.dzonicasa.xyz/dzoni/codex-cli-shared.git`
+
+**On session START** (before any work):
+```
+cd ~/codex-cli-shared && git pull --ff-only 2>/dev/null || git clone https://git.dzonicasa.xyz/dzoni/codex-cli-shared.git ~/codex-cli-shared
+```
+Then read `AGENTS.md`, `network-topology.md`, and relevant `HANDOFF*.md` from the repo.
+
+**On session END** (after saving session):
+```
+cd ~/codex-cli-shared
+cp ~/codex-cli/projects/*/HANDOFF.md HANDOFF_*.md 2>/dev/null
+cp ~/codex-cli/_shared/contexts/network-topology.md _shared_contexts_network-topology.md 2>/dev/null
+git add -A && git commit -m "session: $(date +%Y-%m-%d_%H%M%S) — <project>" && git push
+```
+
+**No cron, no daemons** — just two git commands per session. Zero overhead when idle.
 
 ### Handoff protocol (when switching models mid-project):
 - Example: codex started building an API, then crashed. User opens deepseek.