feat: expose atomic UniFi tools and RF diagnostics

[jmagar]

Summary

• project all registered UniFi capabilities as 267 atomic MCP tools while retaining the legacy unifi(action=..., params=...) router as deprecated compatibility
• add typed client RF/statistics tools, including unifi_get_client_stats, unifi_get_client_wifi_details, and get_client_rf_history
• correct historical client reports to POST /stat/report/{granularity}.user with typed time-range/report bodies
• correlate current client state, historical RF samples, paginated system-log association/roam/disconnect events, and current AP radio context
• enforce capability-derived auth scopes for atomic dispatch and expand schema/dispatch/request-construction coverage
• update README, CLAUDE.md, UniFi skill guidance, API coverage, and endpoint verification docs for the atomic surface

Verification

• cargo fmt --check
• git diff --check
• just validate-plugin
• cargo test
• cargo clippy --workspace --all-targets -- -D warnings
• cargo run -p xtask -- verify-api-endpoints --mode contract
  • 253 endpoints accounted
  • 237 contract-ok
  • 16 fixture-required
  • 0 rejected

Fixes #36