feat: Implement Mattermost sync functionality and enhance workspace context management

scripts/mattermost/README.md

@@ -0,0 +1,52 @@
+# Mattermost Sync
+
+This directory contains the workspace-local Mattermost extractor used by OpenCode to refresh communication context.
+
+## Files
+
+- `mattermost_context.py`
+  Extracts recent Mattermost messages as JSONL.
+- `sync.sh`
+  Stable wrapper intended to be called by OpenCode.
+- `.env.example`
+  Example configuration without secrets.
+- `requirements.txt`
+  Reserved for future optional dependencies.
+
+## Recommended Setup
+
+1. Copy `.env.example` to `.env`.
+2. Fill in your Mattermost values.
+3. Create a local virtual environment if you want an isolated runtime.
+
+Example:
+
+```bash
+cd scripts/mattermost
+bash bootstrap.sh
+```
+
+## Usage
+
+Manual run:
+
+```bash
+bash scripts/mattermost/sync.sh
+```
+
+OpenCode can use this script directly. If `FIDELITY_MATTERMOST_SYNC_CMD` is not set, the workspace plugins will fall back to this wrapper automatically.
+
+## Bootstrap
+
+You can initialize the local runtime with:
+
+```bash
+bash scripts/mattermost/bootstrap.sh
+```
+
+This will:
+
+- create `.venv/` if missing
+- create `.env` from `.env.example` if needed
+
+The current extractor uses only the Python standard library, so no third-party install is required.