refactor(factory): replace Pi pipeline with Kit

[walker-tx]

Summary

• replace the Pi/TypeScript guide factory with one Kit 0.1.98 coordinator using OpenRouter openai/gpt-5.6-sol at high reasoning effort
• keep deterministic Git, GitHub, validation, publication, stale-sweep, and recovery operations in reviewed Bash/Go boundaries
• isolate OpenRouter, Pulse, GitHub, SSH, and local repository credentials from the model container; restrict Exa to coordinator research
• remove the retired TypeScript pipeline and phase-lock files, switching to whole-guide reruns
• add secure GitHub Actions workflows, local drafting, operator documentation, and offline regression coverage

Verification

• GOFLAGS='-ldflags=-linkmode=external' bash factory/tests/run.sh — 8/8 passed
• GOFLAGS='-ldflags=-linkmode=external' bash go/check.sh — passed
• ShellCheck 0.10.0 — passed
• actionlint 1.7.7 — passed
• pinned Linux/AMD64 image reports kit 0.1.98, contains the static guide linter, and contains no Go runtime
• active retired-reference, guide-lock, whitespace, and credential-boundary audits — passed

Notes

• No paid OpenRouter or Exa smoke test was run. The opt-in local procedure is documented in FACTORY.md.
• On this macOS host, Go 1.22.12 verification required external linking because of the known missing LC_UUID linker issue.