diff --git a/backend/app/db/init_db.py b/backend/app/db/init_db.py
index 14b96a2..062973e 100644
--- a/backend/app/db/init_db.py
+++ b/backend/app/db/init_db.py
@@ -414,6 +414,50 @@ async def ensure_drop_category_tables(engine: AsyncEngine) -> None:
     logger.info("category taxonomy tables dropped (attributes / ref units / conversions)")
 
 
+async def ensure_rbac_schema(engine: AsyncEngine) -> None:
+    """Panel-access schema (pm branch): users.username, projects planning
+    columns, user_panels and user_project_members. Idempotent; safe on any
+    volume — the RBAC model expects these and login 500s without them."""
+    stmts = (
+        "ALTER TABLE users ADD COLUMN IF NOT EXISTS username TEXT",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS location TEXT DEFAULT ''",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS project_manager TEXT DEFAULT ''",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS planned_start DATE",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS planned_end DATE",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS actual_start DATE",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS actual_end DATE",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS status TEXT DEFAULT 'ACTIVE'",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS progress DOUBLE PRECISION DEFAULT 0.0",
+        "ALTER TABLE projects ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ DEFAULT now()",
+        """
+        CREATE TABLE IF NOT EXISTS user_panels (
+            id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+            user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+            panel TEXT NOT NULL,
+            level TEXT NOT NULL,
+            created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+            CONSTRAINT uq_user_panel UNIQUE (user_id, panel)
+        )
+        """,
+        "CREATE INDEX IF NOT EXISTS ix_user_panels_user_id ON user_panels(user_id)",
+        """
+        CREATE TABLE IF NOT EXISTS user_project_members (
+            id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+            user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+            project_id UUID NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+            created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+            CONSTRAINT uq_user_project_member UNIQUE (user_id, project_id)
+        )
+        """,
+        "CREATE INDEX IF NOT EXISTS ix_user_project_members_user_id ON user_project_members(user_id)",
+        "CREATE INDEX IF NOT EXISTS ix_user_project_members_project_id ON user_project_members(project_id)",
+    )
+    async with engine.begin() as conn:
+        for stmt in stmts:
+            await conn.execute(text(stmt))
+    logger.info("RBAC schema ensured (username / project columns / user_panels / user_project_members)")
+
+
 async def ensure_audit_table(engine: AsyncEngine) -> None:
     """v2.7: general activity trail (audit_log). Idempotent; safe on any volume."""
     ddl = """
diff --git a/backend/app/main.py b/backend/app/main.py
index aa86a08..be34a9d 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -32,6 +32,7 @@ from app.db.init_db import (
     ensure_dashboard_tables,
     ensure_material_topic_column,
     ensure_quote_projects,
+    ensure_rbac_schema,
     ensure_project_transfers_table,
     ensure_v26,
 )
@@ -107,6 +108,7 @@ async def lifespan(_app: FastAPI):
     await ensure_material_topic_column(engine)
     await ensure_quote_projects(engine)
     await ensure_v26(engine)
+    await ensure_rbac_schema(engine)
     await ensure_audit_table(engine)
     await ensure_drop_category_tables(engine)
     await ensure_bot_drafts_table(engine)