feat(acp): implement ACP server with session lifecycle, tool streaming, and IDE integration (#368)

This commit scaffolds the @moonshot-ai/acp-adapter package and introduces
the full ACP (Agent Communication Protocol) server implementation for
Kimi Code CLI, including:

- Scaffold @moonshot-ai/acp-adapter workspace package with build skeleton
- `kimi acp` CLI subcommand and stdout-safe logging
- ACP version negotiation and AgentSideConnection wrapper
- Auth gate for session creation
- Session lifecycle: new, list, load with history replay
- Prompt content conversion (text, image, embedded resources, resource links)
- Assistant streaming with thinking support and end-turn handling
- Tool call streaming (started, delta, progress) with result conversion (text / diff)
- Approval handling with diff/text display blocks mapped to ACP options
- Kaos read/write interface (AcpKaos) for unsaved buffer access
- Session mode (yolo/auto) and model management
- Config options builder with thinking toggle
- MCP server forwarding from ACP to harness
- Agent plan updates and available commands updates
- AskUserQuestion bridged to session/request_permission
- Plan review options surfaced through requestPermission
- Error mapping, ext_method stubs, and graceful shutdown
- IDE integration guide (Zed + JetBrains)
- End-to-end tests against ACP TS SDK client

flake.nix

@@ -62,6 +62,7 @@
       # pnpmConfigHook (dependencies for that workspace won't be fetched).
       # -------------------------------------------------------------------
       workspacePaths = [
+        ./packages/acp-adapter
         ./packages/agent-core
         ./packages/kaos
         ./packages/kosong
@@ -77,6 +78,7 @@
       ];
 
       workspaceNames = [
+        "@moonshot-ai/acp-adapter"
         "@moonshot-ai/agent-core"
         "@moonshot-ai/kaos"
         "@moonshot-ai/kosong"
@@ -138,7 +140,7 @@
               inherit (finalAttrs) pname version src pnpmWorkspaces;
               inherit pnpm;
               fetcherVersion = 3;
-              hash = "sha256-HpRlxlXZoVqAzrdMdSWhLcTRM1DvDvytVbzIGBo8QUo=";
+              hash = "sha256-/Kgq76JAgi1NygbnYkBNACUl+U9TO5zwF1MaCzk3n9o=";
             };
 
             nativeBuildInputs = [