Fix TRV status ingestion: subscribe to live shellies/+/status topic

The firmware actually running on the deployed TRVs (SHTRV-01 v2.2.4,
confirmed against live hardware) publishes a combined status blob on
shellies/<id>/status, not the per-field shellies/<id>/thermostat/0/target_t
topic handleStatus() was written against — so current_target_temp was
permanently NULL and the dashboard modal always showed "—".

Adds handleStatusBlob() to parse the real payload shape and populate
current_target_temp/current_room_temp/battery_pct. This firmware also has
no guest-vs-automation 'source' field, so guest detection is redesigned to
diff an incoming target_t against a new last_commanded_target_t column,
stamped by publishTarget() right before every command is sent. A mismatch
means the guest changed it via the dial; a match means it's an echo of our
own automation.

Old handleStatus()/topicMatchesStatus() path left in place, dormant —
harmless if some future firmware does use per-field topics.

TRV command topic (shellies/<id>/thermostat/0/command/target_t) is still
unverified against live hardware — flagged in code comments.

backend/src/db.js

@@ -176,6 +176,13 @@ export async function initDb() {
   await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS remote_locked BOOLEAN`)
   await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS status_updated_at TIMESTAMPTZ`)
 
+  // Live TRV firmware (SHTRV-01 v2.2.4, confirmed 2026-08-25) publishes a combined
+  // status blob with no guest-vs-automation 'source' field the old archived logic
+  // relied on. Guest detection is done by diffing an incoming target_t against the
+  // last value hvac itself commanded — stamped here right before every publish, read
+  // back in mqtt.js's status handler. A mismatch = guest changed it via the dial.
+  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS last_commanded_target_t NUMERIC(4,1)`)
+
   // Default-template rollout: existing installs created occupied_temp/vacant_temp/
   // heating_offset_min/cooling_offset_min as NOT NULL with a hardcoded default — relax
   // that so NULL can mean "inherit the global hvac_defaults template" (see seedDefaults()

backend/src/lib/mqtt.js

@@ -224,6 +224,52 @@ function topicMatchesInfo(topic) {
   return /^shellies\/(.+)\/info$/.exec(topic)
 }
 
+function topicMatchesStatusBlob(topic) {
+  return /^shellies\/(.+)\/status$/.exec(topic)
+}
+
+// shellies/<id>/status -> the LIVE topic this firmware (SHTRV-01 v2.2.4, confirmed
+// 2026-08-25) actually publishes: a combined blob, not the per-field topic
+// handleStatus() above was written against ({"tmp":{"value":22.6,"units":"C",
+// "is_valid":true},"target_t":{"enabled":true,"value":10.0,"units":"C"},
+// "temperature_offset":0.0,"bat":72}). No 'source' field exists on this firmware —
+// guest-vs-automation is inferred by diffing target_t against last_commanded_target_t
+// (stamped by publishTarget() right before every command we send). No prior command
+// on record (fresh device, nothing commanded yet) -> 'unknown', not a guessed guess.
+async function handleStatusBlob(externalRef, payload) {
+  const roomTemp = payload.tmp?.value
+  const targetTemp = payload.target_t?.value
+  const battery = payload.bat
+
+  try {
+    const { rows } = await pool.query(
+      `SELECT last_commanded_target_t FROM zone_devices WHERE device_type = 'shelly_trv' AND external_ref = $1`,
+      [externalRef]
+    )
+    const lastCommanded = rows[0]?.last_commanded_target_t
+    let origin = 'unknown'
+    if (targetTemp != null && lastCommanded != null) {
+      origin = Math.abs(Number(lastCommanded) - targetTemp) < 0.1 ? 'automation' : 'guest'
+    }
+
+    await pool.query(
+      `UPDATE zone_devices
+       SET current_target_temp = $2, current_room_temp = $3, battery_pct = $4,
+           target_origin = $5, last_seen = NOW(), status_updated_at = NOW(), updated_at = NOW()
+       WHERE device_type = 'shelly_trv' AND external_ref = $1`,
+      [externalRef, targetTemp ?? null, roomTemp ?? null, battery ?? null, origin]
+    )
+
+    if (origin === 'guest' && targetTemp != null) {
+      await syncGuestAdjustmentToRoom(externalRef, targetTemp).catch(err => {
+        console.error('[mqtt] guest valve sync failed:', err.message)
+      })
+    }
+  } catch (err) {
+    console.error('[mqtt] failed to record status blob update:', err.message)
+  }
+}
+
 // shellies/<id>/info -> full Gen1 status snapshot, republished on every state change.
 // For TRVs (SHTRV-01) this carries thermostats[0].tmp.value (actual sensed room temp)
 // and thermostats[0].pos (valve position 0-100, >0 = actively calling for heat) — the
@@ -362,6 +408,7 @@ export async function connect() {
         console.log('[mqtt] connected to broker')
         c.subscribe([
           'shellies/announce', 'shellies/+/settings', 'shellies/+/thermostat/0/target_t', 'shellies/+/info',
+          'shellies/+/status', // live combined-blob topic (see handleStatusBlob) — the real path
           'hvac/mhi/+/status/+', // MHI aircon status (retained per-signal JSON)
         ])
         resolve()
@@ -392,6 +439,11 @@ export async function connect() {
           handleStatus(statusMatch[1], payload).catch(() => {})
           return
         }
+        const statusBlobMatch = topicMatchesStatusBlob(topic)
+        if (statusBlobMatch) {
+          handleStatusBlob(statusBlobMatch[1], payload).catch(() => {})
+          return
+        }
         const infoMatch = topicMatchesInfo(topic)
         if (infoMatch) {
           handleInfo(infoMatch[1], payload).catch(() => {})
@@ -430,9 +482,20 @@ export function getDiscoveredDevices() {
 }
 
 // Publish a setpoint command to a single TRV. Does NOT wait for acknowledgment —
-// use setTargetWithRetry() for the full reliability pipeline.
+// use setTargetWithRetry() for the full reliability pipeline. Stamps
-function publishTarget(externalRef, tempC) {
+// last_commanded_target_t BEFORE publishing so handleStatusBlob() has something to
+// diff the device's next status report against (this firmware has no 'source' field
+// to read instead — see handleStatusBlob for the full explanation).
+// UNVERIFIED against live hardware: this command topic is carried over from the old
+// per-field scheme, which this firmware's STATUS side has already proven not to use —
+// confirm this is actually what the device accepts before relying on it in the UI.
+async function publishTarget(externalRef, tempC) {
   if (!client?.connected) throw new Error('MQTT broker not connected')
+  await pool.query(
+    `UPDATE zone_devices SET last_commanded_target_t = $2, target_origin = 'pending'
+     WHERE device_type = 'shelly_trv' AND external_ref = $1`,
+    [externalRef, tempC]
+  ).catch(err => console.error('[mqtt] failed to stamp last_commanded_target_t:', err.message))
   const topic = `shellies/${externalRef}/thermostat/0/command/target_t`
   client.publish(topic, String(tempC))
 }
@@ -477,7 +540,7 @@ export async function setTargetWithRetry(device, tempC) {
 
   for (let attempt = 0; attempt < RETRY_DELAYS_MS.length; attempt++) {
     try {
-      publishTarget(externalRef, tempC)
+      await publishTarget(externalRef, tempC)
     } catch (err) {
       console.error(`[mqtt] publish failed for ${externalRef}:`, err.message)
     }
@@ -501,7 +564,7 @@ export async function setTargetWithRetry(device, tempC) {
   // All MQTT retries exhausted — try HTTP wake-up before giving up
   const wokeUp = await tryHttpWakeUp(deviceIp)
   if (wokeUp) {
-    try { publishTarget(externalRef, tempC) } catch { /* ignore */ }
+    try { await publishTarget(externalRef, tempC) } catch { /* ignore */ }
     const acked = await waitForAck(externalRef, tempC, 30000)
     if (acked) return true
   }