Initial commit: opencode_bridge JupyterLab extension (Slices 1-3.5)

A JupyterLab extension that bridges the cell UI to a local OpenCode Serve
process. The extension is a dual package: a Python server extension
exposed under /opencode-bridge/*, plus a TypeScript frontend that
registers per-cell toolbars.

Backend (Python, tornado)
- Slice 1: config + auth + OpenCode HTTP client (tornado.httpclient,
  no aiohttp). 4 settings in schema/plugin.json (url, user, password,
  request timeout).
- Slice 2: handlers for /hello, /health, /providers, /edit.
- Slice 2.1 (correction): SessionManager with 1 notebook = 1 session
  mapping, async-safe via per-path locks, 404 recovery via invalidate().
  Two new endpoints: GET /sessions, DELETE /session?notebook=<path>.
- 32 pytest tests pass.

Frontend (TypeScript, JupyterLab 4.6)
- src/types.ts: CellContext, OpenCodeRequest/Response, OpenCodeSettings.
- src/context/cell_context.ts: extract CellContext from a CodeCell +
  its parent NotebookPanel, structured error collection.
- src/api/opencode_client.ts: callOpenCodeEdit, callOpenCodeProviders.
- src/components/opencode_cell_footer.ts: OpenCodeCellFooter Widget
  implementing ICellFooter with 3 buttons (optimize / fix / edit),
  resolved via this.parent instanceof CodeCell. NOT cellToolbar
  (does not exist in JL 4.6) and NOT Widget.findParent (removed in
  @lumino/widgets 2.x).
- src/components/opencode_cell_factory.ts: Cell.ContentFactory
  subclass returning the OpenCodeCellFooter.
- src/components/opencode_installer.ts: installOpenCodeEverywhere
  patches every notebook (existing + new) to use the custom factory.
- src/index.ts: registers the factory, loads settings, fetches
  /providers on activation and logs the list to the console.
- 23 jest tests pass (mocked JupyterLab boundary, pnpm path safe).

Settings
- 6 fields: 3 auth (url/user/password) + 1 timeout + 2 model selection
  (provider/model). Provider list is fetched at startup from
  /opencode-bridge/providers and printed to the browser console so
  users can copy values into Settings Editor.

Docs
- design.md: 6 sections covering architecture, UI flow, API contract,
  TS skeletons, session management (v0.2.1 correction), and
  provider/model selection (v0.2.2 addition).
- CLAUDE.md: agent guidance for working in this repo.
- TODO.md: remaining work for Slices 4-7 + v0.4+ backlog.

CI
- Gitea release workflow at .github/workflows/build.yml.
- Bark notification helper (non-fatal on failure).

Generated artefacts ignored: opencode_bridge/labextension/, _version.py,
*.tsbuildinfo, junit.xml, test.ipynb scratch notebook.

.github/scripts/create-release.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# create-release.sh — create a Gitea release and attach dist/ assets.
+#
+# Required env vars (set by the workflow):
+#   GITEA_TOKEN    Gitea API token with release write scope
+#   TAG_NAME       tag name (e.g. v0.0.1-beta)
+#   API_URL        Gitea API base URL (e.g. http://gitea.local/api/v1)
+#   REPOSITORY     owner/repo
+#   SHA            commit SHA the tag points at
+
+set -euo pipefail
+
+PAYLOAD=$(cat <<EOF
+{
+  "tag_name": "${TAG_NAME}",
+  "target_commitish": "${SHA}",
+  "name": "Release ${TAG_NAME}",
+  "body": "Auto-generated release assets.",
+  "draft": false,
+  "prerelease": false
+}
+EOF
+)
+
+echo "Creating Gitea release for tag ${TAG_NAME}..."
+
+RELEASE_RESPONSE=$(curl -fsS -X POST "${API_URL}/repos/${REPOSITORY}/releases" \
+  -H "accept: application/json" \
+  -H "authorization: token ${GITEA_TOKEN}" \
+  -H "Content-Type: application/json" \
+  -d "${PAYLOAD}")
+
+RELEASE_ID=$(printf '%s' "${RELEASE_RESPONSE}" | grep -oP '"id":\s*\K[0-9]+' | head -n 1)
+if [ -z "${RELEASE_ID}" ]; then
+  echo "ERROR: failed to create release. Response:"
+  echo "${RELEASE_RESPONSE}"
+  exit 1
+fi
+echo "Release created with ID ${RELEASE_ID}"
+
+for asset in dist/snapshot-*.whl dist/snapshot-*.tar.gz; do
+  if [ -f "${asset}" ]; then
+    echo "Uploading ${asset}..."
+    curl -fsS -X POST "${API_URL}/repos/${REPOSITORY}/releases/${RELEASE_ID}/assets" \
+      -H "accept: application/json" \
+      -H "authorization: token ${GITEA_TOKEN}" \
+      -F "attachment=@${asset}"
+    echo
+  else
+    echo "Skipping ${asset} (not found)"
+  fi
+done