demo: P1 — search filter now actually filters by state and role

The Co-Pilot search box read state and role from the dropdowns (#sst, #srl)
but appended them to the message string as ' in '+st. The server's NL
parser then matched the literal preposition "in" against the case-insensitive
regex /\b(IL|IN|...)\b/i and assigned state IN (Indiana) to every search.
Result: typing "forklift in IL" returned Indiana workers. Same for WI, TX,
any state — all silently became Indiana. That was the "cached/generic
response" the legacy staffing client was seeing.

Two prongs:

1. search.html doSearch() now passes structured fields:
     {message, state, role}
   instead of munging into the message text. Dropdown selections bypass
   NL parsing entirely.

2. /intelligence/chat smart_search route accepts those structured fields
   and prefers them over regex archaeology. Falls back to NL parsing only
   when fields aren't provided. Fixed the regex too: the prepositional
   form (?:in|from)\s+(STATE) wins, the standalone form requires uppercase
   (drops /i flag) so the lowercase preposition "in" can no longer match.

Verified live:
- POST /intelligence/chat {"message":"forklift","state":"IL"}
    → 167 IL forklift operators (Galesburg, Joliet, ...)
- POST /intelligence/chat {"message":"forklift","state":"WI","role":"Forklift Operator"}
    → 16 WI Forklift Operators (Milwaukee, Madison, ...)
- POST /intelligence/chat {"message":"forklift in IL"} (NL fallback)
    → 167 IL workers (regex now correctly distinguishes preposition from state code)

Playwright drove the live UI through devop.live/lakehouse and confirmed the
front-end posts the structured body and the result panel renders the right
state. Restart sequence: kill old bun :3700, bun run mcp-server/index.ts.

mcp-server/search.html

@@ -2274,13 +2274,15 @@ function doSearch(){
   var q=document.getElementById('sq').value.trim();if(!q)return;
   lastQuery=q;
   var st=document.getElementById('sst').value,rl=document.getElementById('srl').value;
-  // Append dropdown filters to the query so the smart parser picks them up
-  var fullQ=q;
-  if(st&&q.indexOf(st)<0)fullQ+=' in '+st;
-  if(rl&&q.toLowerCase().indexOf(rl.toLowerCase())<0)fullQ+=' '+rl;
+  // Pass dropdown filters as structured fields. Old code appended
+  // ' in '+st to the message, which the server misparsed: the
+  // preposition "in" matched the regex for state code "IN" (Indiana)
+  // and every search returned Indiana workers regardless of dropdown.
+  // Sending structured state/role lets the server skip NL parsing
+  // for those fields entirely.
   var out=document.getElementById('sresults');out.textContent='Finding the best matches...';
   fetch(A+'/intelligence/chat',{method:'POST',headers:{'Content-Type':'application/json'},
-  body:JSON.stringify({message:fullQ})
+  body:JSON.stringify({message:q,state:st||undefined,role:rl||undefined})
   }).then(function(r){return r.json()}).then(function(d){
     out.textContent='';
     // Show what the system understood