#135 docs: add CONTRIBUTING.md with agent-friendly context

[Anonymous]

Originally created by: kumaakh

Background

Suggested in PR [#133] by the contributor. CLAUDE.md currently references CONTRIBUTING.md but the file does not exist.

What to include

• How to run tests (npm test)
• How to run a dev-mode install (node dist/index.js install)
• PR process (branch → PR → CI must pass → squash merge)
• Good first issues label and pointer to the issue tracker
• Agent-specific guidance: which files are safe to edit, what the fleet skill files are for, how to test skill changes

Why

Without this file, first-time contributors (human or AI) have no clear entry point. The broken reference in CLAUDE.md also signals an incomplete repo.

[Anonymous]

Originally posted by: kumaakh

CONTRIBUTING.md already exists at the repo root — the premise of this issue was wrong, filed without checking. The real gap (agent-specific guidance in CONTRIBUTING.md) is tracked in [#140].

[Anonymous]

Ticket changed by: kumaakh

• status: open --> closed