Shorten setup guides

[moinulmoin]

Summary

• replace the long agent setup script with a seven-line handoff that points back to the README
• rely on the bundled skill for ongoing search and retrieval behavior
• reduce the human quick start to install, start, search, and doctor
• keep the detailed commands, permissions, privacy, and troubleshooting guidance in the sections below

Impact

The setup section is 81 lines shorter without removing the information readers need after initial setup.

Validation

• README passes Prettier and git diff checks
• 134 Python tests pass
• TypeScript, Raycast lint, and Raycast build pass
• npm audit reports 0 vulnerabilities
• local retrieval eval: 98% Recall@5, 0 negative failures
• local search benchmark: 174.7 ms p95 against the 250 ms gate