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_analysis.py

@@ -10,6 +10,10 @@ class FlAnalysis(models.Model):
     case_id = fields.Many2one(
         'fl.case', ondelete='cascade', index=True
     )
+    analysis_type = fields.Selection([
+        ('engine', 'AI Engine Analysis'),
+        ('attorney', 'Attorney Strategy Memo'),
+    ], string='Analysis Type', default='engine')
     analysis_date = fields.Datetime(
         string='Analysis Date',
         default=fields.Datetime.now
@@ -36,6 +40,23 @@ class FlAnalysis(models.Model):
         help='Resumen en español — sin jerga legal'
     )
 
+    # ── Attorney Strategy Memo ─────────────────────────────────────────────
+    strategy_memo = fields.Html(
+        string='Strategy Memo',
+        help='Substantive strategy memo authored by the Attorney agent.'
+    )
+    risk_narrative = fields.Text(
+        string='Risk Narrative',
+        help='Narrative of substantive risks: DV, hidden assets, income '
+             'imputation, unrepresented respondent, etc.'
+    )
+    cited_statute_ids = fields.Many2many(
+        'fl.statute',
+        'fl_analysis_statute_rel',
+        'analysis_id', 'statute_id',
+        string='Cited Statutes'
+    )
+
     # ── Analysis Detail (Phase 5) ──────────────────────────────────────────
     petitioner_arguments = fields.Text(
         string='Petitioner Arguments (JSON)'