fix: reproducible build — pin deps, patch commander, move stubs to stubs/

- Move private package stubs to stubs/ (tracked), reference via file: in package.json
  Stubs: color-diff-napi, modifiers-napi, @ant/claude-for-chrome-mcp,
         @anthropic-ai/mcpb, @anthropic-ai/sandbox-runtime
- Add patches/commander@14.0.3.patch via pnpm patch:
  Allow multi-char short flags (/^-[^-]+$/) so -d2e works with commander v14
- Pin all dependency versions to exact versions from original cli.js bundle
  (extracted from node_modules package.json files in source map)
- Add @anthropic-ai/bedrock-sdk, foundry-sdk, vertex-sdk to dependencies
- Update .gitignore: node_modules/ fully ignored (regenerated by pnpm install)
- Update scripts to use plain `bun` instead of hardcoded path
- Verified: rm -rf node_modules && pnpm install && bun run build.ts succeeds
  Output: dist/cli.js (22.1MB), `bun dist/cli.js --version` → 2.1.88 (Claude Code)

claude-code-source/stubs/modifiers-napi/index.js

@@ -0,0 +1,3 @@
+export function getModifiers() { return [] }
+export function isModifierPressed() { return false }
+export function prewarm() {}

claude-code-source/stubs/modifiers-napi/package.json

@@ -0,0 +1 @@
+{"name":"modifiers-napi","version":"1.0.0","type":"module","main":"index.js","exports":{".":"./index.js"}}