Phase 1: Migrationsaudit + Forward-Migrationen 0093-0096

Audit (docs/migration_history_audit.md):
- files.size_bytes: INTEGER (Alembic) vs BIGINT (Produktion/Plugin)
- GIN-Indizes: Fehlendes USING GIN in Alembic 0002
- guest_users: ix_guest_users_email_tenant fehlt UNIQUE in Alembic 0059
- plugins.name: Doppelter Unique-Index in Produktion

Forward-Migrationen:
- 0093: files.size_bytes INTEGER → BIGINT
- 0094: GIN-Indizes reparieren + plugins.name doppelten Index entfernen
- 0095: guest_users email+tenant_id UNIQUE INDEX (mit Dubletten-Check)
- 0096: Workspace tenant_integrity (tenant-bound FKs)

Tests: 41/41 bestanden (17 Workspace + 24 Command)
Alembic Head: 0096

alembic/versions/0093_fix_files_size_bytes_bigint.py

@@ -0,0 +1,34 @@
+"""Fix files.size_bytes type: INTEGER → BIGINT.
+
+The DMS plugin migration (0001_initial.sql) created size_bytes as BIGINT,
+but Alembic migration 0071 created it as INTEGER.
+Production already has BIGINT (from plugin migration).
+This migration aligns Alembic with production.
+
+Revision ID: 0093
+Revises: 0092
+"""
+
+from __future__ import annotations
+
+from alembic import op
+
+revision = "0093"
+down_revision = "0092"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Align size_bytes with production (BIGINT)
+    op.execute(
+        "ALTER TABLE IF EXISTS files "
+        "ALTER COLUMN size_bytes TYPE BIGINT"
+    )
+
+
+def downgrade() -> None:
+    op.execute(
+        "ALTER TABLE IF EXISTS files "
+        "ALTER COLUMN size_bytes TYPE INTEGER"
+    )

alembic/versions/0094_fix_gin_indexes_and_plugins_dedup.py

@@ -0,0 +1,53 @@
+"""Fix GIN indexes and remove duplicate plugins.name index.
+
+Alembic 0002 created search indexes without USING GIN.
+Production already has GIN indexes (corrected by later migrations or manual).
+This migration ensures GIN indexes exist for both fresh install and existing DBs.
+
+Also removes the redundant ix_plugins_name unique index (plugins_name_key
+already enforces uniqueness from the column definition).
+
+Revision ID: 0094
+Revises: 0093
+"""
+
+from __future__ import annotations
+
+from alembic import op
+
+revision = "0094"
+down_revision = "0093"
+branch_labels = None
+depends_on = None
+
+# GIN indexes that should exist with USING GIN
+GIN_INDEXES = [
+    ("contacts", "ix_contacts_search_tsv", "search_tsv"),
+    ("audit_log", "ix_audit_log_search_tsv", "search_tsv"),
+    ("calendar_entries", "ix_cal_entries_search_tsv", "search_tsv"),
+    ("comm_messages", "ix_comm_messages_search_tsv", "search_tsv"),
+    ("files", "ix_files_content_tsv", "content_tsv"),
+    ("mails", "ix_mails_body_tsv", "body_tsv"),
+    ("tags", "ix_tags_search_tsv", "search_tsv"),
+]
+
+
+def upgrade() -> None:
+    # Fix GIN indexes: drop and recreate with USING GIN (idempotent)
+    for table, index_name, column in GIN_INDEXES:
+        op.execute(f"DROP INDEX IF EXISTS {index_name}")
+        op.execute(
+            f"CREATE INDEX IF NOT EXISTS {index_name} "
+            f"ON {table} USING gin ({column})"
+        )
+
+    # Remove redundant plugins.name index (plugins_name_key already enforces uniqueness)
+    op.execute("DROP INDEX IF EXISTS ix_plugins_name")
+
+
+def downgrade() -> None:
+    # Recreate the dropped index without GIN (not truly reversible to wrong state)
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_plugins_name ON plugins (name)"
+    )
+    # GIN indexes cannot be meaningfully downgraded to non-GIN

alembic/versions/0095_fix_guest_users_unique.py

@@ -0,0 +1,54 @@
+"""Fix guest_users email+tenant_id unique index.
+
+Alembic 0059 created ix_guest_users_email_tenant as a normal (non-unique) index.
+The SQLAlchemy model defines it as unique=True, and production already has
+a UNIQUE INDEX. This migration aligns Alembic with production.
+
+Before creating the unique index, checks for duplicate (email, tenant_id) pairs.
+If duplicates exist, the migration aborts with a data cleanup report.
+
+Revision ID: 0095
+Revises: 0094
+"""
+
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0095"
+down_revision = "0094"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Check for duplicates before creating unique index
+    conn = op.get_bind()
+    duplicates = conn.execute(
+        sa.text(
+            "SELECT email, tenant_id, count(*) FROM guest_users "
+            "GROUP BY email, tenant_id HAVING count(*) > 1"
+        )
+    ).fetchall()
+
+    if duplicates:
+        raise RuntimeError(
+            f"Cannot create unique index: {len(duplicates)} duplicate (email, tenant_id) pairs found. "
+            "Data cleanup required before migration."
+        )
+
+    # Drop the non-unique index and recreate as unique
+    op.execute("DROP INDEX IF EXISTS ix_guest_users_email_tenant")
+    op.execute(
+        "CREATE UNIQUE INDEX IF NOT EXISTS ix_guest_users_email_tenant "
+        "ON guest_users (email, tenant_id)"
+    )
+
+
+def downgrade() -> None:
+    op.execute("DROP INDEX IF EXISTS ix_guest_users_email_tenant")
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_guest_users_email_tenant "
+        "ON guest_users (email, tenant_id)"
+    )

alembic/versions/0096_workspace_tenant_integrity.py

@@ -0,0 +1,93 @@
+"""Workspace tenant integrity constraints.
+
+Plan 4.3: Add tenant-bound foreign keys to workspace child tables.
+
+- workspaces: UNIQUE (tenant_id, id)
+- workspace_modules: FK (tenant_id, workspace_id) → workspaces (tenant_id, id)
+- workspace_widgets: FK (tenant_id, workspace_id) → workspaces (tenant_id, id)
+- workspace_users: FK (tenant_id, workspace_id) → workspaces (tenant_id, id)
+- workspace_users: FK (tenant_id, user_id) → user_tenants (tenant_id, user_id)
+
+Revision ID: 0096
+Revises: 0095
+"""
+
+from __future__ import annotations
+
+from alembic import op
+
+revision = "0096"
+down_revision = "0095"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # 1. Add UNIQUE (tenant_id, id) on workspaces
+    op.execute(
+        "CREATE UNIQUE INDEX IF NOT EXISTS uq_workspaces_tenant_id "
+        "ON workspaces (tenant_id, id)"
+    )
+
+    # 2. Drop existing FKs on workspace_modules (workspace_id → workspaces.id)
+    #    and replace with tenant-bound FK
+    op.execute("ALTER TABLE workspace_modules DROP CONSTRAINT IF EXISTS workspace_modules_workspace_id_fkey")
+    op.execute(
+        "ALTER TABLE workspace_modules "
+        "ADD CONSTRAINT fk_wm_tenant_workspace "
+        "FOREIGN KEY (tenant_id, workspace_id) "
+        "REFERENCES workspaces (tenant_id, id) ON DELETE CASCADE"
+    )
+
+    # 3. Drop existing FK on workspace_widgets and replace with tenant-bound FK
+    op.execute("ALTER TABLE workspace_widgets DROP CONSTRAINT IF EXISTS workspace_widgets_workspace_id_fkey")
+    op.execute(
+        "ALTER TABLE workspace_widgets "
+        "ADD CONSTRAINT fk_ww_tenant_workspace "
+        "FOREIGN KEY (tenant_id, workspace_id) "
+        "REFERENCES workspaces (tenant_id, id) ON DELETE CASCADE"
+    )
+
+    # 4. Drop existing FK on workspace_users and replace with tenant-bound FK
+    op.execute("ALTER TABLE workspace_users DROP CONSTRAINT IF EXISTS workspace_users_workspace_id_fkey")
+    op.execute(
+        "ALTER TABLE workspace_users "
+        "ADD CONSTRAINT fk_wu_tenant_workspace "
+        "FOREIGN KEY (tenant_id, workspace_id) "
+        "REFERENCES workspaces (tenant_id, id) ON DELETE CASCADE"
+    )
+
+    # 5. Add FK on workspace_users (tenant_id, user_id) → user_tenants (tenant_id, user_id)
+    op.execute(
+        "ALTER TABLE workspace_users "
+        "ADD CONSTRAINT fk_wu_tenant_user "
+        "FOREIGN KEY (tenant_id, user_id) "
+        "REFERENCES user_tenants (tenant_id, user_id) ON DELETE CASCADE"
+    )
+
+
+def downgrade() -> None:
+    # Remove tenant-bound FKs, restore simple FKs
+    op.execute("ALTER TABLE workspace_users DROP CONSTRAINT IF EXISTS fk_wu_tenant_user")
+    op.execute("ALTER TABLE workspace_users DROP CONSTRAINT IF EXISTS fk_wu_tenant_workspace")
+    op.execute(
+        "ALTER TABLE workspace_users "
+        "ADD CONSTRAINT workspace_users_workspace_id_fkey "
+        "FOREIGN KEY (workspace_id) REFERENCES workspaces (id) ON DELETE CASCADE"
+    )
+
+    op.execute("ALTER TABLE workspace_widgets DROP CONSTRAINT IF EXISTS fk_ww_tenant_workspace")
+    op.execute(
+        "ALTER TABLE workspace_widgets "
+        "ADD CONSTRAINT workspace_widgets_workspace_id_fkey "
+        "FOREIGN KEY (workspace_id) REFERENCES workspaces (id) ON DELETE CASCADE"
+    )
+
+    op.execute("ALTER TABLE workspace_modules DROP CONSTRAINT IF EXISTS fk_wm_tenant_workspace")
+    op.execute(
+        "ALTER TABLE workspace_modules "
+        "ADD CONSTRAINT workspace_modules_workspace_id_fkey "
+        "FOREIGN KEY (workspace_id) REFERENCES workspaces (id) ON DELETE CASCADE"
+    )
+
+    op.execute("DROP INDEX IF EXISTS uq_workspaces_tenant_id")

docs/migration_history_audit.md

@@ -0,0 +1,91 @@
+# Migration History Audit
+
+**Erstellt:** 2026-08-03
+**Alembic-Head:** 0092
+**Produktions-Stand:** 0092
+
+---
+
+## Bestätigte Schema-Diskrepanzen
+
+### 1. files.size_bytes — Typ-Diskrepanz
+
+| Quelle | Typ |
+|--------|-----|
+| Alembic 0071 | INTEGER |
+| DMS Plugin Migration 0001 | BIGINT |
+| SQLAlchemy Model | Integer |
+| **Produktion** | **bigint** |
+
+**Klassifizierung:** Echte Schemaänderung
+**Forward-Migration:** 0093 — `ALTER COLUMN size_bytes TYPE BIGINT`
+
+### 2. GIN-Indizes — Fehlendes USING GIN
+
+Alembic 0002 erstellt:
+```sql
+CREATE INDEX ix_companies_search_vec ON companies (search_tsv)
+```
+
+Produktion hat:
+```sql
+CREATE INDEX ix_companies_search_vec ON companies USING gin (search_tsv)
+```
+
+Betroffene Tabellen/Indizes (in Produktion als GIN vorhanden):
+- contacts.ix_contacts_search_tsv
+- audit_log.ix_audit_log_search_tsv
+- calendar_entries.ix_cal_entries_search_tsv
+- comm_messages.ix_comm_messages_search_tsv
+- files.ix_files_content_tsv
+- mails.ix_mails_body_tsv
+- tags.ix_tags_search_tsv
+
+**Klassifizierung:** Echte Schemaänderung (Index-Typ)
+**Forward-Migration:** 0094 — GIN-Indizes neu erstellen mit USING GIN
+
+### 3. guest_users — Fehlender UNIQUE Constraint
+
+Alembic 0059 erstellt:
+```sql
+CREATE INDEX ix_guest_users_email_tenant ON guest_users (email, tenant_id)
+```
+
+Model und Produktion haben:
+```sql
+CREATE UNIQUE INDEX ix_guest_users_email_tenant ON guest_users (email, tenant_id)
+```
+
+**Klassifizierung:** Echte Schemaänderung (Unique fehlt in Alembic)
+**Forward-Migration:** 0095 — Index als UNIQUE neu erstellen
+
+### 4. plugins.name — Doppelter Unique-Index
+
+Produktion hat zwei UNIQUE-Indizes auf plugins.name:
+- `plugins_name_key` (von `unique=True` in Column-Definition)
+- `ix_plugins_name` (von explizitem `CREATE INDEX` in 0003, als UNIQUE in Produktion)
+
+Alembic 0003 erstellt `ix_plugins_name` ohne `UNIQUE`, aber Column hat `unique=True`.
+
+**Klassifizierung:** Nur Idempotenzänderung (Redundanz)
+**Forward-Migration:** 0094 — Doppelten Index entfernen
+
+---
+
+## Keine Diskrepanz gefunden
+
+- tenants.slug: unique=True in 0001 + Model + Produktion → ✅
+- plugin_migrations: UniqueConstraint in 0003 + Model + Produktion → ✅
+- RLS-Policies: Alle korrekt in Produktion → ✅
+- Workspace-Tabellen: RLS fail-closed, Tabellen korrekt → ✅
+
+---
+
+## Forward-Migration-Plan
+
+| Migration | Inhalt |
+|-----------|--------|
+| 0093 | files.size_bytes INTEGER → BIGINT |
+| 0094 | GIN-Indizes reparieren + plugins.name doppelten Index entfernen |
+| 0095 | guest_users email+tenant_id UNIQUE INDEX |
+| 0096 | Workspace tenant_integrity (Plan 4.3) |