Harden MCP tooling: correctness fixes, validation, and new sim/device tools

[maatheusgois-dd]

Summary

A reliability/consistency hardening pass across the MCP tools and CLI, plus new simulator/device tools. Tool count 120 → 125; test suite 575 → 619 passing. Every change was validated against a real Bazel iOS workspace (~/projects/ios) and a booted simulator.

• Correctness: fixed combined stdout/stderr JSON parsing (simctl list, swift package dump-package, idb accessibility snapshot); host-arch-aware iOS simulator CPU (BAZEL_IOS_SIMULATOR_CPU); quote-aware BAZEL_IOS_STARTUP_ARGS; env-overridable discover scope; macOS readBundleId now handles Contents/Info.plist.
• LLDB: per-command output buffer (fixes a deadlock once a session passed 500KB), newline/quote injection guards, session cleanup on server shutdown.
• Consistency: streaming tools return structuredContent; Bazel exit-code annotations; device launch/stop/screenshot now surface error hints + structured content; SPM flag parity (-c/--debug); config keeps string-typed keys as strings.
• New tools: bazel_ios_uninstall_app, bazel_ios_device_uninstall_app, bazel_ios_device_list_apps, bazel_ios_add_media, bazel_ios_get_app_container (+ CLI verbs).
• Scaffold: bundleId/minimumOs/rulesVersion validation, families & bazelVersion options, iOS Info.plist keys, absolute config path.
• DX: doctor reports idb/pymobiledevice3/maxOutput; README env-var section; runtime smoke script + CI smoke step; --version/-h flags; device-app-path CLI.

Note: this branch also snapshots in-progress xcode-native-mcp, command-log, and diagnostics modules that were already present in the working tree. Flagging for reviewers in case they should land separately.

Scope

• MCP server/tools
• CLI commands or parsers
• Bazel build/test/discovery
• Simulator workflows
• Physical device workflows
• UI automation, screenshots, video, logs, or deep links
• LLDB debugging
• macOS, tvOS, watchOS, or visionOS workflows
• Swift Package Manager
• Daemon, session defaults, config, doctor, or setup
• Project scaffolding
• Docs, examples, or agent skills
• CI, release, packaging, or dependencies

Validation

• `npm run lint`
• `npm run typecheck`
• `npm test` (619 passing)
• `npm run build`
• `npm run smoke`
• Manual CLI validation with `xcodebazelmcp ...`
• Simulator validation (add-media, screenshot, ui-dump against booted sim)
• Physical device validation (devices present but no destructive ops run)

Compatibility

• Adds, removes, or renames MCP tools (adds 5; daemon tool descriptions clarified)
• Changes CLI flags, command output, exit codes, or streaming behavior (new verbs, --version/-h, streaming structured content, Bazel exit hints)
• Changes config files, environment variables, defaults, or profiles (new env vars; string-key parsing)
• Changes generated project scaffolding (validation + new options + plist keys)
• Requires updates to docs, README, manifests, schemas, or skills (README updated)

Notes For Reviewers

• New env vars documented in README: `BAZEL_IOS_SIMULATOR_CPU`, `BAZEL_IOS_DISCOVER_SCOPE`, `BAZEL_IOS_MCP_MAX_OUTPUT`, `BAZEL_IOS_STARTUP_ARGS`, `BAZEL_IOS_COMMAND_LOG*`.
• Deliberately not included (recommended as separate PRs): daemon process-ownership rewrite, YAML-library config migration.
• A set_content_size tool was prototyped then removed after live testing showed simctl ui content_size hangs on Xcode 26.3.

Made with Cursor

[codecov]

Codecov Report

❌ Patch coverage is 54.79369% with 745 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/tools/handlers/simulator.ts	42.14%	79 Missing and 2 partials ⚠️
src/cli/commands.ts	0.00%	79 Missing ⚠️
src/cli.ts	0.00%	66 Missing ⚠️
src/tools/handlers/device.ts	32.09%	55 Missing ⚠️
src/doctor-cli.ts	0.00%	47 Missing ⚠️
src/utils/process.ts	64.22%	43 Missing and 1 partial ⚠️
src/tools/handlers/xcode.ts	62.50%	39 Missing ⚠️
src/tools/handlers/macos.ts	24.00%	38 Missing ⚠️
src/core/simulators.ts	55.69%	34 Missing and 1 partial ⚠️
src/core/devices.ts	48.33%	31 Missing ⚠️
... and 23 more

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