Align case stages to 5-stage spec and add Paralegal AI agent

Stage alignment:
- Replace the 11 procedural stages with the spec's 5-stage machine
  (Intake/Active/Discovery/Pre-Trial/Closed); only Closed is folded
- Make fl_stage_data.xml updatable (drop noupdate) so the rename applies on
  upgrade; keep fl_stage_intake/discovery/closed XML ids
- Update case search filters to the new stage names (Intake/Active/Discovery/Pre-Trial)

Issue-tag bug fix (fl_ai_engine):
- Rule-based tagging and caselaw matching compared snake_case keys against the
  human-readable seeded tag names, so they never matched and issue_tag_ids was
  never populated. Add RULE_KEY_TO_TAG_NAME and translate keys to real names
  before all fl.issue.tag / fl.caselaw lookups

Paralegal agent (fl.paralegal.agent, AbstractModel):
- on_stage_change(): fast rule-based pass fired automatically on stage entry and
  case creation — generates the stage task batch (idempotent), recalculates
  filing/service deadlines, cross-references statutes by issue tag + case type,
  posts a chatter summary. No Claude call, so it never blocks the workflow
- run_manual(): full pass adding a best-effort Claude procedural briefing with
  rule-based fallback; wired to a "Paralegal Review" button on the case form
- AI audit-time logging is guarded behind a fl.timesheet existence check
  (model not built yet)
- fl.case.write fires on_stage_change only when stage_id actually changes;
  create() generates the Intake batch

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

activeblue_familylaw/views/fl_case_views.xml

@@ -21,6 +21,9 @@
                         <button name="action_run_conflict_check" string="Run Conflict Check"
                                 type="object"
                                 groups="activeblue_familylaw.group_admin,activeblue_familylaw.group_paralegal"/>
+                        <button name="action_run_paralegal" string="Paralegal Review"
+                                type="object"
+                                groups="activeblue_familylaw.group_admin,activeblue_familylaw.group_paralegal"/>
                     </header>
 
                     <!-- Attorney Referral Banner -->
@@ -350,11 +353,13 @@
                     <filter string="Active Cases" name="active"
                             domain="[('active', '=', True)]"/>
                     <filter string="Intake" name="stage_intake"
-                            domain="[('stage_id.name', '=', 'Intake &amp; Qualification')]"/>
-                    <filter string="Filed" name="stage_filed"
-                            domain="[('stage_id.name', '=', 'Filed — Awaiting Service')]"/>
+                            domain="[('stage_id.name', '=', 'Intake')]"/>
+                    <filter string="Active" name="stage_active"
+                            domain="[('stage_id.name', '=', 'Active')]"/>
                     <filter string="Discovery" name="stage_discovery"
                             domain="[('stage_id.name', '=', 'Discovery')]"/>
+                    <filter string="Pre-Trial" name="stage_pretrial"
+                            domain="[('stage_id.name', '=', 'Pre-Trial')]"/>
                     <separator/>
                     <filter string="Modification Cases" name="type_modification"
                             domain="[('case_type', '=', 'modification')]"/>