feat(fusion_repairs): Bundle 5 - M5 pre-paid service plans + burn-down

New models
- fusion.repair.service.plan.subscription
  Tracks pre-paid maintenance packages: partner, plan product, optional
  category restriction, visits_included / visits_used / visits_remaining,
  start_date / end_date, computed state (active/exhausted/expired/cancelled),
  burn_history One2many. PLAN-NNNNN sequence.
- fusion.repair.service.plan.burn
  One row per maintenance visit that consumed a plan visit - feeds the
  Burn History tab on the subscription form.

product.template extensions
- x_fc_is_service_plan boolean toggle
- x_fc_plan_visits_included (default 4)
- x_fc_plan_duration_months (default 12)
- x_fc_plan_category_id - if set, only burns for repairs in that category
  (e.g. an Annual Stairlift Maintenance plan does not burn for wheelchair
  repairs)

sale.order.action_confirm() override
- For each order line whose product has x_fc_is_service_plan=True,
  spawns one fusion.repair.service.plan.subscription per qty unit.
- Start date = today; end date = today + plan_duration_months
  (relativedelta - correct month boundaries).

Visit report wizard
- New _burn_service_plan_visit(repair) call from action_confirm() finds
  the matching active subscription and burns one visit + posts a chatter
  note "Visit burned for repair X. N of M remaining." on the subscription.
- Skips quote-only repairs.
- The wizard does NOT zero out the invoice - the burn is informational;
  the office reconciles plan credits in their accounting workflow.

Backend
- Service Plans menu under Fusion Repairs root.
- List view colour-coded by state.
- Form with statusbar + cancel button + Burn History notebook.
- Service Plan tab added to product.template form (manager only).
- ACL: User read; Dispatcher write/create; Manager full + unlink.

Verified end-to-end on local westin-v19:
  Created plan product 'Annual Stairlift Maintenance - 4 Visits'
  Sold it via sale.order -> PLAN-00001 auto-created
  (visits_included=4, end_date=2027-05-21)
  Submitted visit-report on a stairlift repair -> visits_used=1
  remaining=3 (correctly category-matched).

Bumped to 19.0.1.5.0.

Co-authored-by: Cursor <cursoragent@cursor.com>

fusion_repairs/security/ir.model.access.csv

@@ -30,3 +30,8 @@ access_repair_inspection_user,Inspection Cert User Read,model_fusion_repair_insp
 access_repair_inspection_dispatcher,Inspection Cert Dispatcher,model_fusion_repair_inspection_certificate,group_fusion_repairs_dispatcher,1,1,1,0
 access_repair_inspection_manager,Inspection Cert Manager Full,model_fusion_repair_inspection_certificate,group_fusion_repairs_manager,1,1,1,1
 access_repair_inspection_technician,Inspection Cert Field Tech Read-Only,model_fusion_repair_inspection_certificate,fusion_tasks.group_field_technician,1,0,0,0
+access_service_plan_sub_user,Service Plan Sub User Read,model_fusion_repair_service_plan_subscription,group_fusion_repairs_user,1,0,0,0
+access_service_plan_sub_dispatcher,Service Plan Sub Dispatcher,model_fusion_repair_service_plan_subscription,group_fusion_repairs_dispatcher,1,1,1,0
+access_service_plan_sub_manager,Service Plan Sub Manager Full,model_fusion_repair_service_plan_subscription,group_fusion_repairs_manager,1,1,1,1
+access_service_plan_burn_user,Service Plan Burn User Read,model_fusion_repair_service_plan_burn,group_fusion_repairs_user,1,0,0,0
+access_service_plan_burn_manager,Service Plan Burn Manager Full,model_fusion_repair_service_plan_burn,group_fusion_repairs_manager,1,1,1,1