feat: implement proto-gen platform

- Config loader with env var expansion and validation
- SQLite database with tasks and toolchain_versions tables
- Gitea REST API client for repository and branch operations
- K8s client for Job lifecycle management (with noop fallback for local dev)
- REST API: tasks CRUD, retry, plugins, version management
- Worker/scheduler with polling, concurrency control, and job tracking
- Static frontend: generate, tasks, settings pages
- Toolchain images: Go and Node.js Dockerfiles with entrypoint scripts
- Helm chart with deployment, service, configmap, ingress, PVC
- Multi-stage Dockerfile for service
- Unit tests for config, database, gitclient, k8s, api, worker
- E2E tests for idempotency, version switch, failure recovery

toolchains/go/entrypoint.sh

@@ -0,0 +1,60 @@
+#!/bin/sh
+set -e
+
+echo "=== Proto-Gen Go Toolchain ==="
+echo "PROTO_REPO: ${PROTO_REPO}"
+echo "PROTO_BRANCH: ${PROTO_BRANCH}"
+echo "TARGET_REPO: ${TARGET_REPO}"
+
+REPO_DIR=$(mktemp -d)
+OUT_DIR=${OUT_DIR:-/out}
+mkdir -p "${OUT_DIR}"
+
+echo "--- Cloning proto repository ---"
+git clone --branch "${PROTO_BRANCH}" --depth 1 \
+    "https://${GIT_TOKEN}@${GIT_BASE_URL}/${PROTO_REPO}.git" "${REPO_DIR}/proto"
+
+PROTO_SHA=$(cd "${REPO_DIR}/proto" && git rev-parse HEAD)
+echo "Proto commit: ${PROTO_SHA}"
+
+echo "--- Running protoc ---"
+PROTO_FILES=$(find "${REPO_DIR}/proto" -name "*.proto" -type f)
+for proto_file in ${PROTO_FILES}; do
+    protoc \
+        --proto_path="${REPO_DIR}/proto" \
+        --go_out="${OUT_DIR}" --go_opt=paths=source_relative \
+        --go-grpc_out="${OUT_DIR}" --go-grpc_opt=paths=source_relative \
+        "${proto_file#${REPO_DIR}/proto/}"
+done
+
+echo "--- Cloning target repository ---"
+TARGET_DIR=$(mktemp -d)
+if git clone "https://${GIT_TOKEN}@${GIT_BASE_URL}/${TARGET_REPO}.git" "${TARGET_DIR}/target" 2>/dev/null; then
+    echo "Target repo exists"
+else
+    echo "Creating target repository..."
+    curl -s -X POST \
+        -H "Authorization: token ${GIT_TOKEN}" \
+        -H "Content-Type: application/json" \
+        -d "{\"name\": \"${TARGET_REPO}\", \"auto_init\": false}" \
+        "${GIT_BASE_URL}/api/v1/user/repos"
+    git clone "https://${GIT_TOKEN}@${GIT_BASE_URL}/${TARGET_REPO}.git" "${TARGET_DIR}/target"
+fi
+
+echo "--- Checking for changes ---"
+cd "${TARGET_DIR}/target"
+cp -r "${OUT_DIR}"/* . 2>/dev/null || true
+git add -A
+
+if git diff --cached --quiet; then
+    echo "No changes detected, idempotent exit"
+    exit 0
+fi
+
+echo "--- Committing and pushing ---"
+git config user.email "proto-gen@bot"
+git config user.name "Proto-Gen Bot"
+git commit -m "gen(go): from ${PROTO_REPO}@${PROTO_SHA}"
+git push origin "${PROTO_BRANCH}"
+
+echo "=== Done ==="