Drop stdio MCP; keep process spawning and eval out of the bundle

[Leo310]

Summary

Follow-up to #465 for the two behaviour findings that came from bundled dependencies rather than our code: Shell Execution (child_process) and Dynamic Code Execution (new Function). After this PR the production bundle contains no child_process, spawn, execFile, eval( or new Function at all (verified by grepping build/prod/main.js), and it is ~140 kB smaller.

MCP is HTTP-only

• The server modal loses the transport picker and the command / arguments / environment fields; pasting a stdio config into it is refused with an explanation instead of silently importing.
• MCPTransportType is "http" only; MCPStdioServerConfig is gone. The agent editor, data store and AgentManager.loadMCPTools drop their stdio branches (MCP now loads identically on desktop and mobile).
• Data migration v12 → v13 removes any stored stdio server (with a unit test).

Build-time module shims (vite.config.ts → src/lib/shims/)

A small shimModules Vite plugin matches on resolved module paths and swaps four dependency modules:

• @modelcontextprotocol/sdk/client/stdio.js → throws if ever constructed (removes child_process + cross-spawn).
• @modelcontextprotocol/sdk/validation/ajv-provider.js → the SDK's own @cfworker/json-schema provider, which interprets schemas instead of compiling them with new Function. Tool-result validation still runs.
• @anthropic-ai/sdk/tools/agent-toolset/node.mjs → a stub. This is the SDK's local bash/grep/skills toolset; its worker environment imports it dynamically, so Vite inlined it even though nothing here calls it. It was the last child_process user.
• Pixi's five code-generator modules (unsafeEvalSupported, createUboSyncFunction, generateShaderSyncCode, generateUniformsSync, generateParticleUpdateFunction) → stubs; pixiRenderer.ts imports pixi.js/unsafe-eval, Pixi's supported eval-free implementation, so the stubs are never reached.
• The one remaining literal child_process.spawn was a doc string in @langchain/mcp-adapters' stdio option schema; the plugin rewords it in that module only.

Docs to update (site repo)

agents/mcp.md and help/troubleshooting.md on smartsecondbrain.dev still describe the stdio transport and its mobile caveat; both need trimming to HTTP-only.

Test plan

• bun run check, format, lint, test (1652 passing), bun run build
• Bundle grep: 0 × child_process / spawn( / execFile / eval( / new Function
• Live (slot vault): smart graph renders on the eval-free Pixi path, no console errors
• Live: add / edit / test-connect an HTTP MCP server; open an agent that previously had a stdio server and confirm it is gone after migration

[greptile-apps]

Greptile Summary

This PR removes stdio MCP support and keeps process-spawning and dynamic-code dependencies out of the production bundle.

• Restricts stored and runtime MCP configuration to HTTP and migrates existing stdio entries away.
• Replaces dependency modules that introduce process spawning or generated code with explicit build-time shims.
• Uses Pixi’s supported eval-free rendering path.
• Adds production-bundle checks that fail the build when required shims stop matching or forbidden capabilities reappear.
• Updates MCP configuration UI, storage conversion, types, and migration tests accordingly.

Confidence Score: 5/5

The PR appears safe to merge; no outstanding blocking or non-blocking code issue remains.

No new actionable defects were established. The previous SSE finding was correctly withdrawn, the bundle-shim invariant is now enforced during production builds, and the credential-probe and save-gating findings were fully addressed in the current code.

Important Files Changed

Filename	Overview
vite.config.ts	Adds resolved-module shimming and production bundle validation for process-spawning and dynamic-code patterns.
src/components/modal/MCPServerModal.svelte	Converts MCP setup to HTTP-only configuration with guarded automatic connection probing.
src/stores/dataMigrations.ts	Adds schema migration v13 to remove persisted stdio MCP servers.
src/agent/AgentManager.ts	Removes the platform-specific stdio branch and initializes MCP uniformly with HTTP server configurations.
src/components/graph/pixiRenderer.ts	Installs Pixi’s eval-free implementation before renderer creation.
src/lib/shims/mcpJsonSchemaValidator.ts	Replaces AJV’s generated-code validator with the SDK’s interpreted CFWorker provider.
src/types/plugin.ts	Narrows the persisted MCP configuration model to HTTP transport only.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
  A[Stored agent MCP configuration] --> B[v12 to v13 migration]
  B --> C{Transport}
  C -->|stdio| D[Remove server entry]
  C -->|HTTP| E[Keep server entry]
  E --> F[AgentManager]
  F --> G[HTTP MCP client]
  H[Vite dependency resolution] --> I[stdio transport shim]
  H --> J[CFWorker schema validator shim]
  H --> K[Anthropic toolset shim]
  H --> L[Pixi no-eval shims]
  I --> M[Production bundle]
  J --> M
  K --> M
  L --> M
  M --> N[Forbidden-pattern validation]

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