feat: extend scanner language support for mobile dev (stacked on #10)

[smk508]

Hey — this is a stacked follow-up to #10. @levnikmyskin's patch adds .dart to CODE_EXTENSIONS in src/scanner/anatomy-scanner.ts:44; I wanted to extend that to cover the rest of the Flutter toolchain (Kotlin, Swift, ObjC) and a few other common gaps, and fix a small drift issue I spotted in the same area.

This PR is stacked on #10, so the commit history here is @levnikmyskin's unchanged .dart commit followed by mine. If #10 merges first, I'll rebase and this diff will shrink to only the net-new additions. If this one lands first, #10 becomes a no-op.

The context

CODE_EXTENSIONS isn't a file-inclusion gate — it only controls which chars-per-token ratio estimateTokens uses (3.5 for code, 3.75 fallback, 4.0 for prose). A .dart file was already being scanned and written to anatomy.md before #10; its token count was just ~7% low because it fell through to the default ratio. Same is true today for .kt, .swift, .m, .mm, and plenty of others. Worth flagging in case the framing of "add dart support" made the change sound bigger than it is.

The drift

There are actually two near-identical extension sets in the repo:

1. CODE_EXTENSIONS in src/scanner/anatomy-scanner.ts:41 — used by the anatomy scanner's internal estimateTokens.
2. CODE_EXTS in src/tracker/token-estimator.ts:3 — used by the exported detectContentType() helper that other parts of the codebase consume.

They drifted apart the moment #10 added .dart to the first set only. This PR brings them back in sync (.dart is added to CODE_EXTS here) and drops a one-line // Keep in sync with ... comment above each set so the coupling is visible to the next person who touches either file.

The additions

Added to both sets (.dart was already in CODE_EXTENSIONS from #10 and is newly added to CODE_EXTS here):

• Flutter toolchain: .kt, .kts, .swift, .m, .mm
• C++ variants: .hpp, .hh, .cc, .cxx
• Other common languages: .cs, .rb, .php, .lua
• Web frontend: .vue, .svelte, .html, .htm
• Schema / infra: .proto, .graphql, .gql, .tf
• Shell variants: .bash, .zsh, .fish

No behavioral change beyond the ratio swap — description-extractor.ts already handles per-language description extraction for Kotlin, Swift, Dart, Ruby, C#, PHP, etc. via its own path.extname() routing, so nothing else needs touching.

Testing

Environment: macOS Darwin 25.3.0, Node 22, pnpm build pipeline unchanged.

Scratch Flutter layout used for rows 5–6:

<tmp>/lib/main.dart                                 (285 bytes, stateless MyApp widget)
<tmp>/android/app/src/main/kotlin/MainActivity.kt   (171 bytes, FlutterActivity subclass)
<tmp>/ios/Runner/AppDelegate.swift                  (227 bytes, FlutterAppDelegate subclass)

#	Scenario	Result
1	pnpm build	Clean — tsc + hooks + vite dashboard build all green
2	node dist/bin/openwolf.js --help	Prints usage, no errors
3	detectContentType("foo.kt" / ".swift" / ".m" / ".mm" / ".dart") on upstream/main	All return "mixed" (falls through to 3.75 ratio)
4	Same calls on this branch	All return "code" (3.5 ratio)
5	buildAnatomy() on scratch Flutter layout, upstream/main	MainActivity.kt ~46 tok, AppDelegate.swift ~61 tok, main.dart ~76 tok
6	Same on this branch	MainActivity.kt ~49 tok, AppDelegate.swift ~65 tok, main.dart ~82 tok — +6.5%, +6.6%, +7.9% respectively
7	660-char Dart sample through estimateTokens(text, "mixed") vs estimateTokens(text, "code")	176 → 189 tokens (+7.4%)
8	anatomy.md section/description output on scratch project	Kotlin/Swift/Dart descriptions extracted correctly by the existing description-extractor.ts (no change needed there)

Rows 3 and 5 were captured by temporarily reverting both files to upstream/main on the same branch, running the same node one-liners, then restoring.