fix: close missing triple-quote on _build_prompt f-string (SyntaxError)

The f-string in _build_prompt was never closed — the }} at end of the
JSON template was missing the closing \"\"\". Python consumed the entire
rest of the file as f-string content, then tried to evaluate the
{\s\S} regex braces as an f-string expression, giving
"unexpected character after line continuation character".

Also bundles the earlier timeout fixes (SSL handshake, DNS, analyze_site
90s cap, _assess_one 180s cap, worker reset of stale running jobs).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/replicate_ai.py

@@ -123,7 +123,7 @@ Respond ONLY with valid JSON, no markdown fences, no text outside the JSON:
   "services_needed": ["service1","service2"],
   "urgency_signals": ["specific urgent issues like 'SSL expires in 12 days', 'lorem ipsum on homepage', 'no cookie banner'"],
   "outreach_notes": "sales rep context"
-}}
+}}"""
 
 
 def _parse_output(raw: str) -> dict: