feat(tenancy): add merchant team CRUD with multi-store hub view

The merchant team page was read-only. Now merchant owners can invite,
edit roles, and remove team members across all their stores from a
single hub view.

Architecture: No new models — delegates to existing store_team_service.
Members are deduplicated across stores with per-store role badges.

New:
- 5 API endpoints: GET team (member-centric), GET store roles, POST
  invite (multi-store), PUT update role, DELETE remove member
- merchant-team.js Alpine component with invite/edit/remove modals
- Full CRUD template with stats cards, store filter, member table
- 7 Pydantic schemas for merchant team request/response
- 2 service methods: validate_store_ownership, get_merchant_team_members
- 25 new i18n keys across 4 tenancy locales + 1 core common key

Tests: 434 tenancy tests passing, arch-check green.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/routes/api/merchant.py

@@ -168,11 +168,127 @@ async def merchant_team_overview(
     db: Session = Depends(get_db),
 ):
     """
-    Get team members across all stores owned by the merchant.
+    Get team members across all merchant stores (member-centric view).
 
-    Returns a list of stores with their team members grouped by store.
+    Returns deduplicated members with per-store role info.
     """
-    return merchant_store_service.get_merchant_team_overview(db, merchant.id)
+    return merchant_store_service.get_merchant_team_members(db, merchant.id)
+
+
+@_account_router.get("/team/stores/{store_id}/roles")
+async def merchant_team_store_roles(
+    store_id: int,
+    current_user: UserContext = Depends(get_current_merchant_api),
+    merchant=Depends(get_merchant_for_current_user),
+    db: Session = Depends(get_db),
+):
+    """Get available roles for a specific store."""
+    from app.modules.tenancy.services.store_team_service import store_team_service
+
+    merchant_store_service.validate_store_ownership(db, merchant.id, store_id)
+    roles = store_team_service.get_store_roles(db, store_id)
+    return {"roles": roles, "total": len(roles)}
+
+
+@_account_router.post("/team/invite")
+async def merchant_team_invite(
+    data: "MerchantTeamInvite",
+    current_user: UserContext = Depends(get_current_merchant_api),
+    merchant=Depends(get_merchant_for_current_user),
+    db: Session = Depends(get_db),
+):
+    """Invite a member to one or more merchant stores."""
+    from app.modules.tenancy.schemas.team import (
+        MerchantTeamInviteResponse,
+        MerchantTeamInviteResult,
+    )
+    from app.modules.tenancy.services.store_team_service import store_team_service
+
+    # Get the User ORM object (service needs it as inviter)
+    inviter = merchant_store_service.get_user(db, current_user.id)
+
+    results = []
+    for store_id in data.store_ids:
+        try:
+            store = merchant_store_service.validate_store_ownership(
+                db, merchant.id, store_id
+            )
+            store_team_service.invite_team_member(
+                db,
+                store=store,
+                inviter=inviter,
+                email=data.email,
+                role_name=data.role_name,
+            )
+            results.append(MerchantTeamInviteResult(
+                store_id=store.id,
+                store_name=store.name,
+                success=True,
+            ))
+        except Exception as e:
+            results.append(MerchantTeamInviteResult(
+                store_id=store_id,
+                store_name=getattr(e, "store_name", str(store_id)),
+                success=False,
+                error=str(e),
+            ))
+
+    success_count = sum(1 for r in results if r.success)
+    if success_count == len(results):
+        message = f"Invitation sent to {data.email} for {success_count} store(s)"
+    elif success_count > 0:
+        message = f"Invitation partially sent ({success_count}/{len(results)} stores)"
+    else:
+        message = "Invitation failed for all stores"
+
+    return MerchantTeamInviteResponse(
+        message=message,
+        email=data.email,
+        results=results,
+    )
+
+
+@_account_router.put("/team/stores/{store_id}/members/{user_id}")
+async def merchant_team_update_role(
+    store_id: int,
+    user_id: int,
+    role_name: str = Query(..., description="New role name"),
+    current_user: UserContext = Depends(get_current_merchant_api),
+    merchant=Depends(get_merchant_for_current_user),
+    db: Session = Depends(get_db),
+):
+    """Update a member's role in a specific store."""
+    from app.modules.tenancy.services.store_team_service import store_team_service
+
+    store = merchant_store_service.validate_store_ownership(db, merchant.id, store_id)
+    store_team_service.update_member_role(
+        db,
+        store=store,
+        user_id=user_id,
+        new_role_name=role_name,
+        actor_user_id=current_user.id,
+    )
+    return {"message": "Role updated successfully"}
+
+
+@_account_router.delete("/team/stores/{store_id}/members/{user_id}", status_code=204)
+async def merchant_team_remove_member(
+    store_id: int,
+    user_id: int,
+    current_user: UserContext = Depends(get_current_merchant_api),
+    merchant=Depends(get_merchant_for_current_user),
+    db: Session = Depends(get_db),
+):
+    """Remove a member from a specific store."""
+    from app.modules.tenancy.services.store_team_service import store_team_service
+
+    store = merchant_store_service.validate_store_ownership(db, merchant.id, store_id)
+    store_team_service.remove_team_member(
+        db,
+        store=store,
+        user_id=user_id,
+        actor_user_id=current_user.id,
+    )
 
 
 @_account_router.get("/profile", response_model=MerchantPortalProfileResponse)