release: prepare Solodeveling 0.3.1

[ohmiler]

Summary

• harden Quick routing, bounded authority, failure handling, stale-memory recovery, and implementation/release separation
• add deterministic friction scenarios, optional field metrics, byte-exact lifecycle rollback, and tighter skill token budgets
• bump compatible package surfaces to 0.3.1 and add checkout-stable LF policy for reproducible candidate resources

Verification

• 289 Python tests passed
• skill suite, project memory, managed Codex runtime, dependency, compile, and diff checks passed
• npm launcher: 8 passed, 1 Windows symlink capability skip
• source-bound Python candidate verified across autocrlf=true/false clean checkouts
• exact-source Windows x64 native and installed-wheel smoke passed

Limitations

• no live model or comparative field benchmark was run
• Tier 1 cross-runtime behavior and platform signing remain unverified
• this PR does not tag, publish, deploy, or create an immutable release