refactor: restructure to plugin/ + services/ layout and add per-turn bootstrap injection

- Migrate src/ → plugin/ (plugin/core/, plugin/web/, plugin/commands/)
  and src/mcp/ → services/ per OpenClaw plugin dev spec
- Add Gemini CLI backend (plugin/core/gemini/sdk-adapter.ts) with GEMINI.md
  system-prompt injection
- Inject bootstrap as stateless system prompt on every turn instead of
  first turn only: Claude via --system-prompt, Gemini via workspace/GEMINI.md;
  eliminates isFirstTurn branch, keeps skills in sync with OpenClaw snapshots
- Fix session-map-store defensive parsing (sessions ?? []) to handle bare {}
  reset files without crashing on .find()
- Add docs/TEST_FLOW.md with E2E test scenarios and expected outcomes
- Add docs/claude/BRIDGE_MODEL_FINDINGS.md with contractor-probe results

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugin/core/contractor/metadata-resolver.ts

@@ -0,0 +1,33 @@
+import type { ContractorAgentMetadata } from "../types/contractor.js";
+
+const CONTRACTOR_MODEL = "contractor-agent/contractor-claude-bridge";
+
+type AgentConfig = {
+  id: string;
+  workspace?: string;
+  model?: string;
+};
+
+/**
+ * Determine whether an agent is a contractor-backed Claude agent and return its metadata.
+ * Contractor agents are identified by their model string — we do NOT use a custom
+ * runtime.type because OpenClaw's schema only allows "embedded" or "acp".
+ * Returns null if the agent is not contractor-backed.
+ */
+export function resolveContractorAgentMetadata(
+  agentConfig: AgentConfig,
+  permissionMode: string,
+): ContractorAgentMetadata | null {
+  if (agentConfig.model !== CONTRACTOR_MODEL) return null;
+
+  const workspace = agentConfig.workspace;
+  if (!workspace) return null;
+
+  return {
+    agentId: agentConfig.id,
+    contractor: "claude",
+    bridgeModel: "contractor-claude-bridge",
+    workspace,
+    permissionMode,
+  };
+}