Merge feat/l1-workspace into integration branch

# Conflicts:
#	frontend/src/router.tsx

backend/app/core/audit.py

@@ -13,13 +13,20 @@ async def log_audit(
     resource_id: Optional[UUID] = None,
     details: Optional[dict] = None,
     account_id: Optional[UUID] = None,
+    acting_as: Optional[str] = None,
 ) -> None:
-    """Record an audit log entry. Does not commit — piggybacks on the caller's commit."""
+    """Record an audit log entry. Does not commit — caller's commit picks it up.
+
+    acting_as: optional tag from the session (e.g. 'l1_coverage' for engineers
+    on the L1 surface, None for native l1_tech users).
+    """
     if account_id is None:
         # Derive from the acting user's account as a fallback (one extra query).
         from sqlalchemy import select
         from app.models.user import User
-        result = await db.execute(select(User.account_id).where(User.id == user_id))
+        result = await db.execute(
+            select(User.account_id).where(User.id == user_id)
+        )
         account_id = result.scalar_one()
 
     entry = AuditLog(
@@ -29,5 +36,6 @@ async def log_audit(
         resource_type=resource_type,
         resource_id=resource_id,
         details=details,
+        acting_as=acting_as,
     )
     db.add(entry)

backend/app/core/permissions.py

@@ -1,11 +1,12 @@
 """
 Centralized permission checks for ResolutionFlow.
 
-Role hierarchy: super_admin > owner > engineer > viewer
+Role hierarchy: super_admin > owner > engineer > l1_tech > viewer
 
 - super_admin: is_super_admin=True, full system access
 - owner:       account_role='owner', manage account resources
 - engineer:    account_role='engineer' (default), CRUD own trees/steps
+- l1_tech:     account_role='l1_tech', use /l1/* surface only — walk flows, resolve/escalate
 - viewer:      account_role='viewer', read-only (can browse, run sessions, rate steps)
 """
 from __future__ import annotations
@@ -23,7 +24,8 @@ ROLE_HIERARCHY = {
     "super_admin": 4,
     "owner": 3,
     "engineer": 2,
-    "viewer": 1,
+    "l1_tech": 1,
+    "viewer": 0,
 }