Add Attorney AI agent (substantive strategy memo)

- fl.attorney.agent (AbstractModel): manual-only substantive analysis fired from
  the case AI tab. Builds a full case context (parties, children, financials,
  issue tags, prior analyses) plus candidate statute/caselaw lists, and asks
  Claude to author a strategy memo, draft arguments/counterarguments, write a
  risk narrative, and assess substantial change (FL 61.30(1)(b))
- Grounds output in the real library: the model may only pick statutes/case law
  from the supplied candidates, which are then resolved back to records and
  linked (fl.analysis.cited_statute_ids / matched_caselaw_ids, case.caselaw_ids)
- Rule-based fallback produces a usable memo (complexity, statutes by category,
  caselaw by tag, risk flags) when the API is unavailable — never a raw error
- fl.analysis: add analysis_type, strategy_memo (Html), risk_narrative,
  cited_statute_ids; surface them in the analysis views
- fl.case: add attorney_memo_id + related memo/risk display; action_run_attorney_agent
  opens the memo; "Generate Attorney Strategy Memo" button on the AI tab (admin)
- Refactor fl_ai_engine: extract shared call_claude_json(system, user) +
  _extract_json so both agents and the engine share one Claude/JSON path

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

activeblue_familylaw/models/fl_ai_engine.py

@@ -391,9 +391,15 @@ Respond with the JSON object only. No other text."""
     # ──────────────────────────────────────────────────────────────────────────
 
     def _call_claude(self, prompt):
+        """Call Claude with a single user prompt; return parsed JSON dict."""
+        return self.call_claude_json(prompt)
+
+    def call_claude_json(self, user_content, system=None, max_tokens=2048):
         """
-        Call Claude API and return parsed JSON dict.
-        Raises RuntimeError on connection error or JSON parse failure.
+        Shared Claude API entry point used by every agent in this module.
+        Sends `user_content` (optionally with a `system` prompt), parses the
+        response as JSON, and returns a dict. Raises RuntimeError on missing
+        library/key, API error, or JSON parse failure.
         API key read from ir.config_parameter key 'fl_ai.claude_api_key'.
         """
         try:
@@ -410,16 +416,19 @@ Respond with the JSON object only. No other text."""
                 'Set fl_ai.claude_api_key in Settings → Technical → System Parameters.'
             )
 
-        _logger.info("FL AI Engine: calling Claude API (model=%s)", CLAUDE_MODEL)
+        _logger.info("FL AI: calling Claude API (model=%s)", CLAUDE_MODEL)
 
         client = anthropic.Anthropic(api_key=api_key)
+        create_kwargs = {
+            'model': CLAUDE_MODEL,
+            'max_tokens': max_tokens,
+            'messages': [{'role': 'user', 'content': user_content}],
+        }
+        if system:
+            create_kwargs['system'] = system
 
         try:
-            message = client.messages.create(
-                model=CLAUDE_MODEL,
-                max_tokens=2048,
-                messages=[{'role': 'user', 'content': prompt}],
-            )
+            message = client.messages.create(**create_kwargs)
         except anthropic.RateLimitError as exc:
             raise RuntimeError(f'Claude API rate limit exceeded: {exc}') from exc
         except anthropic.APIConnectionError as exc:
@@ -427,10 +436,12 @@ Respond with the JSON object only. No other text."""
         except anthropic.APIError as exc:
             raise RuntimeError(f'Claude API error: {exc}') from exc
 
-        raw = message.content[0].text.strip()
-        _logger.debug("FL AI Engine raw response (first 200 chars): %s", raw[:200])
+        return self._extract_json(message.content[0].text.strip())
+
+    def _extract_json(self, raw):
+        """Strip markdown fences / leading prose and parse the first JSON object."""
+        _logger.debug("FL AI raw response (first 200 chars): %s", raw[:200])
 
-        # Strip markdown code fences if present
         if raw.startswith('```'):
             parts = raw.split('```')
             raw = parts[1] if len(parts) >= 2 else raw
@@ -438,7 +449,6 @@ Respond with the JSON object only. No other text."""
                 raw = raw[4:]
         raw = raw.strip()
 
-        # Extract first JSON object if extra prose leaked through
         if raw and raw[0] == '{':
             brace_depth = 0
             end_idx = 0
@@ -455,7 +465,7 @@ Respond with the JSON object only. No other text."""
         try:
             return json.loads(raw)
         except json.JSONDecodeError as exc:
-            _logger.error("FL AI Engine: JSON parse error: %s\nRaw: %s", exc, raw[:500])
+            _logger.error("FL AI: JSON parse error: %s\nRaw: %s", exc, raw[:500])
             raise RuntimeError(f"Claude returned invalid JSON: {exc}") from exc
 
     # ──────────────────────────────────────────────────────────────────────────