Preserve child-repo guidance and ignore OMX scratch state for the Python SDK

Track the repo-local AGENTS file and ignore OMX scratch state so the Python SDK participates cleanly in the superworkspace workflow while leaving unrelated local docs and Serena edits out of this commit.

Constraint: The SDK repo already has unrelated local work that must be preserved, not mixed into workflow setup
Rejected: Commit quickstart and Serena changes together | unrelated to control-plane hygiene and harder to review safely
Confidence: medium
Scope-risk: narrow
Reversibility: clean
Directive: Review stashed SDK-local work separately before restoring it
Tested: git status --short --branch
Not-tested: pytest validation in this commit lane

Author: viftode4

.gitignore

@@ -15,3 +15,4 @@ venv/
 .env.*
 *.key
 credentials.json
+.omc/

AGENTS.md

@@ -0,0 +1,41 @@
+<!-- OMX:AGENTS-INIT:MANAGED -->
+<!-- Parent: ../AGENTS.md -->
+# trustchain-py
+
+This AGENTS.md scopes guidance to `trustchain-py`. Parent AGENTS guidance still applies unless this file narrows it for this subtree.
+
+## Bootstrap Guardrails
+- This is a lightweight scaffold generated by `omx agents-init`.
+- Refresh updates the layout summary below and preserves the manual notes block.
+- Keep only directory-specific guidance here; do not duplicate the root orchestration brain.
+
+## Current Layout
+
+### Files
+- `.gitignore`
+- `CHANGELOG.md`
+- `CLAUDE.md`
+- `LICENSE`
+- `pyproject.toml`
+- `README.md`
+
+### Subdirectories
+- `.benchmarks/`
+- `.github/`
+- `.omc/`
+- `.pytest_cache/`
+- `.ruff_cache/`
+- `.serena/`
+- `benchmarks/`
+- `docs/`
+- `src/`
+- `tests/`
+
+<!-- OMX:AGENTS-INIT:MANUAL:START -->
+## Local Notes
+- Read `CLAUDE.md` here before making non-trivial changes; it contains the Python SDK parity rules.
+- Verification: `pip install -e \".[dev]\"` then `python -m pytest tests/ -x -q`.
+- Use integer millisecond timestamps only, preserve canonical JSON hashing parity with Rust, and do not call `round()` on trust scores.
+- Use `TrustChainSidecar`, not the deprecated `TrustChainNode`.
+- Rust is authoritative for ambiguous behavior; wire-format changes must stay aligned with `../trustchain` and `../trustchain-js`.
+<!-- OMX:AGENTS-INIT:MANUAL:END -->