Tool tracking now reachable from every shipped surface

The tool tracking module had been shipped for many iterations but wasn't reachable from the in-app navigation — /tools, /tools/[id], and /tools/new existed but the only paths in were deep links and dashboard-card click-throughs. This bundle wires it into every entry point a user actually uses: top nav gains a Tools link (between Mechanic and Map); the global ⌘K search palette fans out to a new /api/search/tools endpoint and returns tools alongside assets with a Tool badge; the /dashboard quick-actions strip adds a Tools button between Log hours and Add asset; the /mechanic role page (where mechanics live) adds a prominent safety-tinted Tools button at the top of its action strip; the homepage hero gets a one-line callout placing tool tracking next to the hardware-tracker mention; /yards now displays "N assets · M tools" per yard (filtered to non-RETIRED); and the /tools empty state explains the module instead of just saying "no tools yet." 7 new contract tests for the tools search helper.