docs: AGENTS.md + evidence-backed scaffold (state, trials, decisions, handoff)

- AGENTS.md operating rules incl. Gitea SSH port-2222 note + known_hosts incident
- CURRENT_STATE / TODO / CHANGELOG / TRIALS
- trials: endpoint-key pairing; config-merge safety matrix 14/14 (verify.sh + output)
- docs: DECISIONS (mcode 0.6.12 bundle facts, digest-pinned), FEATURE-MATRIX, PROJECT-HANDOFF
- handoffs: TEMPLATE + 2026-10-19 initial-install record

TODO.md

@@ -0,0 +1,27 @@
+# TODO
+
+## Now
+
+- [ ] **Visual TUI verification** — user restarts MiniMax Code; confirm the
+  `custom-command` segment renders with Aygea colors, emoji, and no width misalignment.
+  Acceptance: screenshot or user confirmation; move rendering from `inferred` to
+  `confirmed` in `docs/FEATURE-MATRIX.md`.
+- [ ] **Ubuntu rollout ×2** — run the curl one-liner on both Ubuntu boxes; each needs the
+  `zai_api_key` SecretVault secret (or credential.json). Acceptance: `printf '{}' | mcode-zai-usage`
+  prints a segment on both; entry recorded in FEATURE-MATRIX.
+
+## Next
+
+- [ ] **macOS rollout** — same one-liner on the Mac. Script is written portable
+  (`date -r` fallback, no-`flock`/no-`setsid` degrade, `vm_stat` memory) but has never
+  run on macOS: treat as `unknown` until tested. Acceptance: install + segment on macOS.
+- [ ] **mcode-update resilience check** — after the next mcode release, re-grep the new
+  bundle for `customStatusLine`/`statusLineItems` handling and re-check the clamps
+  documented in `docs/DECISIONS.md` D2; update digests there.
+
+## Deferred
+
+- Optional `AYGEA_SL_MEM` memory-segment polish on macOS (page-size assumptions in
+  `vm_stat` parsing are untested there).
+- Consider a `--json` inspection mode for debugging cache state. Rejected for now:
+  scope creep against "little self-contained tool".