fix(xcode-ide): add bridge proxy diagnostics and default schema handling

[dpearson2699]

Summary

Fixes #252

After xcode-ide bridge sync succeeds, paths returned by XcodeGlob are rejected by XcodeRead and RenderPreview with "File not found in project structure". Investigation revealed:

1. The bridge is a pure passthrough -- arguments flow unchanged from client to Apple's remote Xcode MCP server via xcrun mcpbridge. The "File not found" error originates from Apple's remote server, not this codebase.
2. The jsonSchemaToZod converter was silently dropping JSON Schema default values, meaning Zod validation could reject or alter arguments the remote server expects.
3. No diagnostic logging existed in the proxy path, making it impossible to verify what arguments were actually sent/received.

Changes

Bridge proxy diagnostics (registry.ts, tool-service.ts)

• Added debug-level logging at two layers of the proxy call path:
  • registry.ts: Logs tool name and argument keys when the proxy handler is invoked
  • tool-service.ts: Logs call initiation, result summary (content type count), and errors in invokeTool()
• Uses existing log utility at debug level -- zero overhead when debug logging is disabled

JSON Schema default value handling (jsonschema-to-zod.ts)

• Added default to the JsonSchema type definition
• Created applyDefault() helper that chains .default(value) onto any Zod type
• Applied default handling in all type branches (string, number, integer, boolean, array, object)
• This ensures Zod validation preserves default values from remote tool schemas rather than silently dropping them

Integration test for argument passthrough (registry.integration.test.ts)

• Added Echo tool to the fake MCP server fixture that JSON-echoes received arguments
• Added passthrough test verifying: file paths with special characters, unicode strings, extra properties, and boolean/numeric values all survive the proxy round-trip unchanged
• Added explicit tool registration assertion for the Echo tool

Testing

Automated

• All 1496 tests pass, 15 skipped (pre-existing)
• Full pre-commit checklist passed: lint:fix, typecheck, format, build, docs:check, test
• 3-round review: Claude R1 (clean), GPT-5.4 R2 (1 valid finding fixed), Claude R3 (clean)

Manual verification (iOS template project)

• Cloned XcodeBuildMCP-iOS-Template and opened MyProject.xcodeproj in Xcode
• CLI xcode-ide call-tool --remote-tool XcodeGlob returned Swift file paths successfully
• CLI xcode-ide call-tool --remote-tool XcodeRead read files using paths returned by XcodeGlob -- no "File not found" error
• MCP Inspector (npm run inspect): server initialized successfully
• Reloaderoo inspect list-tools: 29 tools registered with xcode-ide workflow enabled, 20 bridge-proxied tools visible
• Reloaderoo inspect call-tool xcode_ide_list_tools: bridge tools returned correctly through MCP proxy path
• XCODEBUILDMCP_DEBUG=true confirmed active in .vscode/mcp.json dev server config

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[dpearson2699]

@cameroncooke can you merge this in?

[cameroncooke]

@dpearson2699 sorry for the delay on this, there is a code freeze on merging contributor PRs at the moment while I finish a very large refactor. I hope to finish my refactor by the end of this week and get this PR in shortly after, I've got a bit of a backlog to address sorry about that.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/xcodebuildmcp@310

commit: 7b7761a

[cameroncooke]

Tried to reproduce #252 on Xcode 26.4 against example_projects/iOS_Calculator and could not — XcodeGlob → XcodeRead/RenderPreview round-trip works cleanly with the project-structure paths returned by XcodeGlob, including the SPM-nested case.

While verifying the PR's stated fix mechanism, also noticed: none of the 20 currently-emitted bridge tools have JSON Schema default keys, so the applyDefault branch added to jsonSchemaToZod is a no-op against the live tool surface. It is still a reasonable defensive change for future schemas, but it cannot be what unblocked #252 in practice.