feat(skills): Phase 1 - Improve critical lang-*-dev skills (2-4/8 → 6+/8)

## Objective

Bring the lowest-scoring `lang-*-dev` skills to minimum viable 8 pillars coverage.

## 8 Pillars

| Pillar | Description |
|--------|-------------|
| Module System | Imports, exports, visibility, packages |
| Error Handling | Error types, Result/Option, exceptions |
| Concurrency | Async/await, threads, channels |
| Metaprogramming | Decorators, macros, annotations |
| Zero/Default Values | Null, undefined, Option, defaults |
| Serialization | JSON, struct tags, validation |
| Build/Deps | Package managers, build tools |
| Testing | Test frameworks, mocking |

## Skills to Improve

| Skill | Current | Target | Missing Pillars |
|-------|---------|--------|-----------------|
| lang-typescript-dev | 2/8 | 7+/8 | Module, Error, Concurrency, Serialization, Build, Testing |
| lang-rust-dev | 4/8 | 6+/8 | Module, Concurrency, Serialization, Build |
| lang-go-dev | 4/8 | 6+/8 | Build, Serialization (complete partials) |
| lang-java-dev | 4/8 | 6+/8 | Module, Concurrency, Build, Testing |
| lang-haskell-dev | 4/8 | 6+/8 | Concurrency, Serialization, Build, Testing |
| lang-objc-dev | 4/8 | 6+/8 | Metaprogramming, Serialization, Build, Testing |
| lang-carbon-dev | 4/8 | 6+/8 | Concurrency, Metaprogramming, Serialization, Testing |

## Content Strategy

- **Pattern-covered pillars** (Concurrency, Serialization, Metaprogramming): 50-80 lines + reference to pattern skill
- **Non-pattern pillars** (Module, Error, Zero, Build, Testing): 80-150 lines comprehensive

## Progress

- [ ] lang-typescript-dev
- [ ] lang-rust-dev
- [ ] lang-go-dev
- [ ] lang-java-dev
- [ ] lang-haskell-dev
- [ ] lang-objc-dev
- [ ] lang-carbon-dev

## Related

- Closes #223 (when all phases complete)
- References pattern skills: PR #226, #227, #228
- Plan: `.claude/plans/wise-beaming-cerf.md`