fix: restore tree dropped by 6d224861; land stem95su gdrive-sync (10m) [ci skip]

6d224861 came from a --no-checkout worktree whose empty index made the
commit drop every file except two. This restores 05b50d2b's full tree and
correctly adds stacks/stem95su/gdrive-sync.tf + the service-catalog stem95su
entry. Forward-only (parent=6d224861, no force-push); [ci skip] since the
live infra was never applied from the broken commit.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/plans/2026-02-23-mailserver-hardening-design.md

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+# Mail Server Lightweight Hardening Design
+
+**Date**: 2026-02-23
+**Scope**: Security, reliability, and hygiene improvements to the docker-mailserver stack
+**Status**: Completed. ForwardEmail relay removed 2026-04-12 — MX now direct to mail.viktorbarzin.me on dedicated MetalLB IP with CrowdSec protection.
+
+## Current State
+
+- docker-mailserver 15.0.0 on K8s (single replica, Recreate strategy)
+- Roundcubemail webmail (MySQL-backed, debug logging on, unpinned :latest tag)
+- Outbound relay via Mailgun, inbound MX via ForwardEmail
+- OpenDKIM for DKIM signing, no spam filtering (SpamAssassin/ClamAV/Amavis disabled)
+- DMARC policy `none` (monitoring only)
+- No brute-force protection, no mailserver-down alert
+- Dovecot exporter sidecar (unpinned), stale SendGrid DNS records
+
+## Changes
+
+### 1. Enable Rspamd (replace OpenDKIM as DKIM signer)
+
+Add to `mailserver_env_config`:
+- `ENABLE_RSPAMD = "1"` (spam filtering, DKIM verification, phishing detection, Oletools)
+- `ENABLE_OPENDKIM = "0"` (Rspamd handles DKIM signing natively)
+- `RSPAMD_LEARN = "1"` (learn from Junk folder movements)
+
+Existing OpenDKIM key mounts stay — Rspamd reads them from the same paths.
+Resource impact: ~150-200MB additional RAM.
+
+### 2. DMARC DNS enforcement
+
+Update `_dmarc` TXT record: `p=none` -> `p=quarantine`. Can tighten to `p=reject` after validation.
+
+### 3. Postfix rate limiting
+
+Add to `postfix_cf`:
+```
+smtpd_client_connection_rate_limit = 10
+smtpd_client_message_rate_limit = 30
+anvil_rate_time_unit = 60s
+```
+
+Service already uses `externalTrafficPolicy: Local`, so real client IPs are visible to Postfix.
+ForwardEmail IPs on port 25 are subject to same limits but 10 conn/min is generous.
+
+### 4. Prometheus alert
+
+Uncomment the existing mailserver-down alert in `prometheus_chart_values.tpl`.
+
+### 5. Roundcubemail cleanup
+
+- Pin image: `roundcube/roundcubemail:latest` -> `roundcube/roundcubemail:1.6-apache`
+- Disable debug: `ROUNDCUBEMAIL_SMTP_DEBUG = "false"`, `ROUNDCUBEMAIL_DEBUG_LEVEL = "1"`
+
+### 6. SendGrid DNS cleanup
+
+Remove stale CNAME records: `em7107`, `s1._domainkey`, `s2._domainkey`.
+
+## Not Changing
+
+- Roundcubemail stays (user preference)
+- ForwardEmail/Mailgun relay stays (practical dependency)
+- ClamAV stays disabled (Rspamd Oletools covers malicious attachments)
+- Single replica (HA email requires significant additional complexity)