diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3e85224..575dc7e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,27 @@
 # Changelog
 
+## 2026-07-06 — vaultwarden F1 fix: _ENABLE_SMTP boot-gate (campaign finding, pilot-blocking)
+
+The no-mercy campaign (felhom.eu `audits/CAMPAIGN-nomercy-2026-07-06.md`, finding F1) proved that a
+FRESH vaultwarden deploy with app-email off — the default state — crash-loops: the template always
+defines `SMTP_HOST=${SMTP_HOST:-}` / `SMTP_FROM=${SMTP_FROM:-}`, and vaultwarden treats a
+defined-but-EMPTY env var as "set", so its config validation (`smtp_host.is_some() ==
+smtp_from.is_empty()`) errors out and the process exits. The old comment ("empty SMTP_HOST = mail
+stays disabled") was wrong for this image. Empirically proven on the pinned
+`vaultwarden/server:1.33.2-alpine` (probe P1: defined-empty pair → exact campaign error, exit 12;
+P2: `_ENABLE_SMTP=false` + same empty pair → boots; P3: `_ENABLE_SMTP=true` + host+from → boots).
+
+Fix: gate the whole SMTP group with vaultwarden's own `_ENABLE_SMTP` flag — compose default
+`false` (validation skipped, mail off, clean boot), flipped to `"true"` by the app-email injection
+via `smtp_mapping.extra` (no controller change needed — `extra` already rides `smtpEnv`). The ON
+path is byte-identical to the previously send-tested state plus the flag.
+
+Sweep note (no edits): the other five smtp-mapped templates (calcom, gitea, mealie, nextcloud,
+rallly) are boot-proven tolerant of defined-empty mail env — all ran healthy as fresh email-off
+deploys during the campaign; gitea's `GITEA__mailer__SMTP_ADDR=${...:-}` pattern likewise.
+Vaultwarden was the only strict image. New REUSE.md trap row: strict images need an enable-flag
+gated `false` in compose + `"true"` in `smtp_mapping.extra`; boot-prove fresh email-off deploys.
+
 ## 2026-07-03 — sparkyfitness FINALIZED + live-validated (both VERIFY markers resolved); REUSE probe-naming row
 
 The first worked example of the new `felhom-app-catalog` skill (felhom.eu). Both
diff --git a/REPORT.md b/REPORT.md
index 8231d9b..2e511f7 100644
--- a/REPORT.md
+++ b/REPORT.md
@@ -1,51 +1,51 @@
-# REPORT — sparkyfitness finalized: image-inspected healthchecks + probe-container naming (2026-07-03)
+# REPORT — vaultwarden F1 fix: `_ENABLE_SMTP` boot-gate (2026-07-06)
 
-**Class:** template finalization + live validation (no version scheme; push = deploy).
-**Baseline:** `main` @ `15cdf7b` → **`c7490f7`**. Companion: the NEW `felhom-app-catalog` skill
-(felhom.eu — this task was its first worked example; see that repo's REPORT for the skill half).
+**Class:** implementation (campaign-finding fix; push = deploy).
+**Baseline:** `main` @ `13eedb1` → (this commit). Provenance: felhom.eu
+`documentation/audits/CAMPAIGN-nomercy-2026-07-06.md` finding **F1** (pilot-blocking: every fresh
+vaultwarden deploy with app-email off — the default — crash-loops).
 
-## What changed
+## Corrected root cause (the campaign report's hypothesis was wrong)
 
-- `templates/sparkyfitness/docker-compose.yml`:
-  - Both `VERIFY-BEFORE-FINALIZE` markers RESOLVED by inspecting the actual images on the demo box
-    (the skill's core rule — never guess):
-    - **frontend** `codewithcj/sparkyfitness:v0.17.2` (Alpine/nginx): has `/usr/bin/wget` (and
-      curl; no node/python3) → the drafted BusyBox-wget `--spider :80/` probe kept, marker
-      replaced with the inspection provenance.
-    - **server** `codewithcj/sparkyfitness_server:v0.17.2`: has node v24.17.0 (and wget+curl) →
-      node-exec GET `:3010/api/health` kept (checks the real status, not mere reachability);
-      `/api/health` proven live: `{"status":"UP"}`.
-  - **Frontend `container_name` renamed `sparkyfitness-frontend` → `sparkyfitness`**: the
-    controller-side probe dials the container named exactly like the stack (fallback = FIRST
-    prefix match — could be the DB). New REUSE.md §2 row records the convention.
-  - Both image tags reconfirmed to resolve (`docker manifest inspect`).
-- `templates/sparkyfitness/.felhom.yml`: mem-sum arithmetic comment added
-  (db 512 + server 1024 + frontend 256 = **1792M** — matches the existing value; nothing corrected).
-- `REUSE.md` §2: NEW "Probe-container naming" row (verified against
-  `felhom-controller/internal/stacks/healthprobe.go` `findProbeContainer`).
+Not "shim sets SMTP_FROM without SMTP_HOST" — with app-email off the shim injects **nothing**. The
+crasher: the template always defines `SMTP_HOST=${SMTP_HOST:-}` and `SMTP_FROM=${SMTP_FROM:-}`;
+vaultwarden's `get_env_str_value` returns `Some("")` for a defined-empty var (**empty counts as
+set**), and with `_enable_smtp` defaulting `true` upstream, its validation
+`smtp_host.is_some() == smtp_from.is_empty()` → `true == true` → config error → exit → crash-loop.
+The old template comment ("empty SMTP_HOST = mail stays disabled") was wrong for this image.
 
-## Live validation (demo guest 9201; method stated per claim)
+## Empirical probe (mandatory gate, run on 180 against the pinned image BEFORE editing)
 
-SparkyFitness was already running from the draft (deployed 4 h earlier, 3× healthy). Applying the
-finalized template used the REAL dashboard UI via the browser bridge: "Sablonok frissítése" (sync
-confirmed by the guest's stacks file gaining the rename, zero VERIFY markers), then the card's
-"Frissítés". Result:
+| Probe | Env | Result |
+|---|---|---|
+| P1 (pre-fix shape) | `SMTP_HOST=` `SMTP_FROM=` (defined-empty) | **exit 12** — *"Both `SMTP_HOST` and `SMTP_FROM` need to be set for email support without `USE_SENDMAIL`"* (exact campaign error) — the image-level red-proof |
+| P2 (fix, OFF) | + `_ENABLE_SMTP=false` | **boots** — "Rocket has launched", running |
+| P3 (fix, ON) | `_ENABLE_SMTP=true` + host + from | **boots** — running (no SMTP connect at boot) |
 
-- Only the renamed frontend was recreated — `sparkyfitness … Up 21 seconds (healthy)`; server + db
-  stayed `Up 4 hours` → **the two `data_key` secrets (API_ENCRYPTION_KEY, BETTER_AUTH_SECRET) were
-  NOT regenerated** (deployed app.yaml/.env untouched, exactly the data_key contract).
-- Docker health: 3/3 healthy. Controller-side probe (via `GET /api/stacks/sparkyfitness`, the same
-  data the UI polls): `healthy: true — http :80/ → 200 (6ms)` against the renamed container.
-- `sparky.demo-felhom.eu` answers **200** via Traefik in-guest (Host-header curl).
-- **Kept deployed** on demo (7.3 option A — expendable box, real catalog app). The data_key
-  secrets exist only in the deployed app.yaml, never committed.
+(P2/P3 needed `I_REALLY_WANT_VOLATILE_STORAGE=true` to bypass the unrelated no-volume guard in the
+bare `docker run`; P1 control re-run with it still crashes on the SMTP error, isolating the cause.)
+Logs: DooPlex `~/campaign-nomercy-2026-07-05/evidence/PROBE-F1/`.
 
-## Notes / observations (not acted on)
+## Changes
 
-- Pre-rename, the controller probe was ALSO green — the prefix fallback happened to pick the
-  frontend. The rename converts luck into the deterministic convention.
-- `paperless-ngx`'s container names match neither the exact nor the prefix rule of its stack name —
-  its controller-side probe likely never runs. Candidate follow-up, not touched.
-- BusyBox `ash` `command -v` silently ignores all but its first argument — inspect one tool per
-  run (now in the skill).
-- App-count drift recorded in the felhom.eu REPORT (53 templates vs website "45+" / category sum 49).
+- `templates/vaultwarden/docker-compose.yml` — `_ENABLE_SMTP=${_ENABLE_SMTP:-false}` added to the
+  SMTP group; the wrong comment replaced with the empty-counts-as-set TRAP note (+ config.json
+  admin-panel precedence note). Nothing else touched.
+- `templates/vaultwarden/.felhom.yml` — `smtp_mapping.extra: _ENABLE_SMTP: "true"` (rides the
+  existing `smtpEnv` extra loop; zero controller change).
+- `REUSE.md` — TRAP appended to the App-email row: strict images need the enable-flag pattern;
+  boot-prove fresh email-off deploys for every new smtp-mapped app.
+- `CHANGELOG.md` — entry incl. the sweep note.
+
+## Sweep note (documentation only, no edits)
+
+calcom, gitea, mealie, nextcloud, rallly (and gitea's `GITEA__mailer__SMTP_ADDR=${...:-}`) are
+**boot-proven tolerant** of defined-empty mail env — all ran healthy as fresh email-off deploys in
+the campaign. Vaultwarden was the only strict image.
+
+## Validation
+
+- Probe gate P1/P2/P3 above (image level).
+- Live pipeline validation (Scenario A fresh email-off deploy healthy; Scenario B toggle ON→OFF
+  regression) executed as part of the controller v0.101.0 deployment — see
+  felhom-controller/REPORT.md for the live evidence.
diff --git a/REUSE.md b/REUSE.md
index 97fabc4..79abbc6 100644
--- a/REUSE.md
+++ b/REUSE.md
@@ -23,7 +23,7 @@ None — this repo is templates/config, not code. See §2/§5.
 | Docker healthcheck — DB/Redis sidecars | `templates/paperless-ngx/docker-compose.yml` (~L107, L129) | postgres: `pg_isready -U <user> -d <db>`; mariadb: `healthcheck.sh --connect --innodb_initialized`; redis: `redis-cli ping`. App container gets `depends_on: <db>: condition: service_healthy`. |
 | Memory convention | `templates/paperless-ngx/docker-compose.yml` (~L71) + `.felhom.yml resources:` | EVERY service has `deploy.resources.limits.memory` (compose is the enforcement). NO `reservations` anywhere. `.felhom.yml mem_limit` = SUM of all containers' limits (see paperless header comment: 768+256+128=1152M); `mem_request` = expected steady-state usage, display-only. |
 | Compose file skeleton | `templates/paperless-ngx/docker-compose.yml` (header) | Header comment (app, domain, DB type, RAM math, Pi), `restart: unless-stopped`, `TZ=Europe/Budapest`, explicit `container_name`, `traefik-public` external network + `<app>-internal` for DBs, Traefik labels with ``Host(`${SUBDOMAIN}.${DOMAIN}`)``, named volumes for DB/config (NVMe), `${HDD_PATH}/appdata/<app>/...` for bulk data, `${USERDATA_PATH}/...` for customer-browsable content. |
-| App-email (SMTP shim) opt-in | `templates/vaultwarden/.felhom.yml` (`smtp_mapping:`) + README.md §smtp_mapping | `smtp_mapping` maps shim host/port/security/from to the app's own env names; compose MUST reference the mapped `${VAR:-}` keys with empty defaults. STARTTLS if the app can accept self-signed certs, else `security_value: "NONE"` plaintext (or the :2526 plaintext listener for STARTTLS-insistent clients — see calcom/nextcloud). |
+| App-email (SMTP shim) opt-in | `templates/vaultwarden/.felhom.yml` (`smtp_mapping:`) + README.md §smtp_mapping | `smtp_mapping` maps shim host/port/security/from to the app's own env names; compose MUST reference the mapped `${VAR:-}` keys with empty defaults. STARTTLS if the app can accept self-signed certs, else `security_value: "NONE"` plaintext (or the :2526 plaintext listener for STARTTLS-insistent clients — see calcom/nextcloud). TRAP: an image that treats defined-but-EMPTY mail vars as "set" (vaultwarden — campaign F1 2026-07-06) needs its own enable-flag gated `false` in compose and flipped `"true"` via `smtp_mapping.extra`; boot-prove a fresh email-off deploy for every new smtp-mapped app. |
 | Probe-container naming | `templates/vaultwarden/docker-compose.yml` (`container_name: vaultwarden`) + `templates/sparkyfitness/` | The controller-side `healthcheck.checks[]` probe dials the container whose **name equals the stack (directory) name exactly**; fallback = the FIRST running prefix-match, which in a multi-container stack can be the DB (verified: `felhom-controller/internal/stacks/healthprobe.go` `findProbeContainer`). So the Traefik-exposed service's `container_name` must be exactly the stack name; sidecars `<app>-db`, `<app>-redis`, …. |
 
 ## 3. Dangerous lookalikes — do NOT copy
diff --git a/templates/vaultwarden/.felhom.yml b/templates/vaultwarden/.felhom.yml
index ce55aaa..eb7fe79 100644
--- a/templates/vaultwarden/.felhom.yml
+++ b/templates/vaultwarden/.felhom.yml
@@ -102,3 +102,7 @@ smtp_mapping:
   extra:
     SMTP_ACCEPT_INVALID_CERTS: "true"
     SMTP_ACCEPT_INVALID_HOSTNAMES: "true"
+    # Boot-gate for Vaultwarden's strict SMTP validation (campaign finding F1, 2026-07-06):
+    # the image errors out when SMTP_HOST/SMTP_FROM are defined-but-empty, so the compose
+    # default is _ENABLE_SMTP=false and this injection flips it on with the rest of the group.
+    _ENABLE_SMTP: "true"
diff --git a/templates/vaultwarden/docker-compose.yml b/templates/vaultwarden/docker-compose.yml
index e64aef8..f5ea8f3 100644
--- a/templates/vaultwarden/docker-compose.yml
+++ b/templates/vaultwarden/docker-compose.yml
@@ -29,7 +29,14 @@ services:
       - WEBSOCKET_ENABLED=true
       - TZ=Europe/Budapest
       # App-email (managed relay). Injected by the controller only when app-email is on
-      # (global + per-app); empty SMTP_HOST = Vaultwarden mail stays disabled. See .felhom.yml smtp_mapping.
+      # (global + per-app); see .felhom.yml smtp_mapping.
+      # TRAP (campaign finding F1, 2026-07-06): Vaultwarden treats a defined-but-EMPTY env var as
+      # "set" — with SMTP_HOST/SMTP_FROM both defined-empty its config validation errors out and
+      # the container crash-loops. The whole SMTP group is therefore gated by _ENABLE_SMTP
+      # (default false = validation skipped, mail off); the controller's app-email injection flips
+      # it to true via smtp_mapping.extra. Note: a config.json saved from the admin panel would
+      # override these env values — not applicable to fresh deploys.
+      - _ENABLE_SMTP=${_ENABLE_SMTP:-false}
       - SMTP_HOST=${SMTP_HOST:-}
       - SMTP_PORT=${SMTP_PORT:-587}
       - SMTP_SECURITY=${SMTP_SECURITY:-off}