refactor(opencode): native SDK tools, drop MCP, trim skills, expand telemetry

Reworks @mem0/opencode-plugin to expose memory operations as native OpenCode
tools (via the @opencode-ai/plugin `tool()` helper, backed by the mem0ai SDK)
instead of delegating to the remote MCP server. Skills load via the `config`
hook (`skills.paths`) instead of being copied into the project `.opencode/`.

- Drop MCP: remove the regex-based MCP tool interception, the bundled
  opencode.json MCP registration, and the cli.ts installer (mem0-opencode bin).
- Native tools: add_memory, search_memories, get_memories, get_memory,
  update_memory, delete_memory, delete_all_memories, delete_entities,
  list_entities, get_event_status.
- Trim skills 16 -> 8 (context-loader, dream, forget, health, peek, pin,
  remember, tour); remove import, export, memory-reviewer, mem0, list-projects,
  switch-project, stats, onboard. De-MCP/onboard wording in kept skills.
- Telemetry: emit the full shared plugin.* schema (adds user_prompt, bash_error,
  pre_compact, session_stop alongside session_start, tool_use); tool_use now
  fires from inside each native tool; add project_hash + os_version props.
- Fix duplicate error-search (single topK:6); correct the documented
  experimental.chat.messages.transform hook name.
- Bump to 0.2.0.

integrations/mem0-plugin/.opencode-plugin/telemetry.test.ts

@@ -47,5 +47,32 @@ describe("opencode telemetry", () => {
     process.env.MEM0_TELEMETRY = "false";
     expect(() => captureEvent("session_start", {}, KEY)).not.toThrow();
     expect(() => captureEvent("session_start", {}, undefined)).not.toThrow();
+    expect(() => captureEvent("session_start", {}, KEY, "proj")).not.toThrow();
+  });
+
+  test("every event carries os_version (matches telemetry.py schema)", () => {
+    const props = buildEvent("session_start", {}, KEY)!
+      .properties as Record<string, unknown>;
+    expect(typeof props.os_version).toBe("string");
+  });
+
+  test("project_hash is sha256(projectId) when a project id is supplied", async () => {
+    const { createHash } = await import("node:crypto");
+    const expected = createHash("sha256").update("acme-repo").digest("hex");
+    const props = buildEvent("session_start", {}, KEY, "acme-repo")!
+      .properties as Record<string, unknown>;
+    expect(props.project_hash).toBe(expected);
+  });
+
+  test("project_hash is omitted when no project id is supplied (no raw ids leak)", () => {
+    const props = buildEvent("session_start", {}, KEY)!
+      .properties as Record<string, unknown>;
+    expect("project_hash" in props).toBe(false);
+  });
+
+  test("expanded event types all use the shared plugin.* namespace", () => {
+    for (const ev of ["user_prompt", "bash_error", "pre_compact", "session_stop"]) {
+      expect(buildEvent(ev, {}, KEY)!.event).toBe(`plugin.${ev}`);
+    }
   });
 });