feat(whatsapp): opt-in forwarding of owner-typed messages in bot mode

In `WHATSAPP_MODE=bot` the bridge currently drops every fromMe inbound
message — they are all assumed to be echoes of our own /send calls.
That makes it impossible for plugins / agents to detect when a human
owner has typed directly into a customer chat from the same WhatsApp
Business account (e.g. via a linked phone or WhatsApp Web).

This adds an opt-in `WHATSAPP_FORWARD_OWNER_MESSAGES` env var.  When
true, the bridge classifies fromMe inbound by looking up `key.id` in a
bounded LRU of recently-sent message IDs (the existing 50-entry echo
suppressor, bumped to 512 and extracted to a testable
`outbound_ids.js` helper).  Hits in the LRU are still dropped (echoes);
misses are forwarded to the Python adapter with `fromOwner: true`.

The Python adapter lifts that flag onto
`MessageEvent.metadata["whatsapp_from_owner"]`.  `metadata` is a new
free-form dict on the event so future per-platform signals don't each
need their own field.  Default behaviour is unchanged: with the env
flag unset, bot mode still drops every fromMe message exactly as
before.

Use cases for downstream consumers:
- Implicit handover activation when the owner replies manually
- Sliding TTL on owner activity (keep an active session alive while
  the owner is engaged)
- Audit trails of owner interventions
- Analytics on human-vs-bot reply ratios

Heuristic limitation (documented in code): the LRU is in-memory.  After
a bridge restart, in-flight delivery receipts of pre-restart sends will
briefly look like owner-typed for a few seconds until the set is
repopulated.  Persisting isn't worth the disk churn — downstream
consumers should treat the flag as best-effort.

Tests:
- tests/gateway/test_whatsapp_from_owner.py (new): adapter sets the
  metadata flag iff the bridge payload has `fromOwner: true`; absent
  otherwise.
- scripts/whatsapp-bridge/outbound_ids.test.mjs (new): LRU bounds,
  eviction order, falsy-id handling.

Backwards compatibility: with the env flag unset, every code path is
identical to before.  No existing deployment is affected.

scripts/whatsapp-bridge/bridge.js

@@ -30,6 +30,7 @@ import { execSync } from 'child_process';
 import { tmpdir } from 'os';
 import qrcode from 'qrcode-terminal';
 import { matchesAllowedUser, parseAllowedUsers } from './allowlist.js';
+import { createOutboundIdTracker } from './outbound_ids.js';
 
 // Parse CLI args
 const args = process.argv.slice(2);
@@ -44,6 +45,23 @@ const WHATSAPP_DEBUG =
   typeof process.env.WHATSAPP_DEBUG === 'string' &&
   ['1', 'true', 'yes', 'on'].includes(process.env.WHATSAPP_DEBUG.toLowerCase());
 
+// Opt-in: when true (and WHATSAPP_MODE === 'bot'), fromMe inbound messages
+// that are NOT echoes of our own /send or /send-media calls are forwarded
+// to the Python adapter with `fromOwner: true`. This lets plugins detect
+// "owner just typed in this customer chat" — needed for handover / sliding
+// TTL flows. Default OFF: existing deployments see no behavior change.
+//
+// Heuristic limitation: we distinguish bot-API-sent from owner-typed by
+// looking up `key.id` in `recentlySentIds` (populated when /send returns).
+// On bridge restart that set is empty, so a few in-flight bot replies may
+// briefly look like owner-typed until they age out. Acceptable; we don't
+// persist the set.
+const FORWARD_OWNER_MESSAGES =
+  typeof process !== 'undefined' &&
+  process.env &&
+  typeof process.env.WHATSAPP_FORWARD_OWNER_MESSAGES === 'string' &&
+  ['1', 'true', 'yes', 'on'].includes(process.env.WHATSAPP_FORWARD_OWNER_MESSAGES.toLowerCase());
+
 const PORT = parseInt(getArg('port', '3000'), 10);
 const SESSION_DIR = getArg('session', path.join(process.env.HOME || '~', '.hermes', 'whatsapp', 'session'));
 // Cache directories: the Python gateway passes the profile-aware paths via
@@ -146,12 +164,7 @@ function splitLongMessage(message, maxLength = MAX_MESSAGE_LENGTH) {
 }
 
 function trackSentMessageId(sent) {
-  if (sent?.key?.id) {
-    recentlySentIds.add(sent.key.id);
-    if (recentlySentIds.size > MAX_RECENT_IDS) {
-      recentlySentIds.delete(recentlySentIds.values().next().value);
-    }
-  }
+  rememberSentId(sent?.key?.id);
 }
 
 function normalizeWhatsAppId(value) {
@@ -205,9 +218,18 @@ const logger = pino({ level: 'warn' });
 const messageQueue = [];
 const MAX_QUEUE_SIZE = 100;
 
-// Track recently sent message IDs to prevent echo-back loops with media
-const recentlySentIds = new Set();
-const MAX_RECENT_IDS = 50;
+// Track recently sent message IDs.  Two purposes:
+//   1. Prevent echo-back loops with media in self-chat mode.
+//   2. (When WHATSAPP_FORWARD_OWNER_MESSAGES=true) distinguish our own
+//      bot-API outbound messages from owner-typed messages on the linked
+//      device so we can forward only the latter.
+// Capacity bounded (see outbound_ids.js) to keep memory flat under
+// sustained sending.
+const recentlySentIds = createOutboundIdTracker(512);
+
+function rememberSentId(id) {
+  recentlySentIds.remember(id);
+}
 
 let sock = null;
 let connectionState = 'disconnected';
@@ -300,23 +322,33 @@ async function startSocket() {
       const senderNumber = senderId.replace(/@.*/, '');
 
       // Handle fromMe messages based on mode
+      let fromOwner = false;
       if (msg.key.fromMe) {
         if (isGroup || chatId.includes('status')) continue;
 
         if (WHATSAPP_MODE === 'bot') {
-          // Bot mode: separate number. ALL fromMe are echo-backs of our own replies — skip.
-          continue;
+          // Bot mode: separate bot number. fromMe inbound is either
+          //   (a) an echo of our own /send (recentlySentIds will catch it), or
+          //   (b) a message the owner typed from their own phone using the
+          //       linked-device session.
+          //
+          // We always drop (a). We drop (b) too unless the operator opts in
+          // via WHATSAPP_FORWARD_OWNER_MESSAGES so existing deployments see
+          // no behavior change.
+          if (recentlySentIds.has(msg.key.id)) continue;
+          if (!FORWARD_OWNER_MESSAGES) continue;
+          fromOwner = true;
+        } else {
+          // Self-chat mode: only allow messages in the user's own self-chat.
+          // WhatsApp now uses LID (Linked Identity Device) format: 67427329167522@lid
+          // AND classic format: 34652029134@s.whatsapp.net
+          // sock.user has both: { id: "number:10@s.whatsapp.net", lid: "lid_number:10@lid" }
+          const myNumber = (sock.user?.id || '').replace(/:.*@/, '@').replace(/@.*/, '');
+          const myLid = (sock.user?.lid || '').replace(/:.*@/, '@').replace(/@.*/, '');
+          const chatNumber = chatId.replace(/@.*/, '');
+          const isSelfChat = (myNumber && chatNumber === myNumber) || (myLid && chatNumber === myLid);
+          if (!isSelfChat) continue;
         }
-
-        // Self-chat mode: only allow messages in the user's own self-chat
-        // WhatsApp now uses LID (Linked Identity Device) format: 67427329167522@lid
-        // AND classic format: 34652029134@s.whatsapp.net
-        // sock.user has both: { id: "number:10@s.whatsapp.net", lid: "lid_number:10@lid" }
-        const myNumber = (sock.user?.id || '').replace(/:.*@/, '@').replace(/@.*/, '');
-        const myLid = (sock.user?.lid || '').replace(/:.*@/, '@').replace(/@.*/, '');
-        const chatNumber = chatId.replace(/@.*/, '');
-        const isSelfChat = (myNumber && chatNumber === myNumber) || (myLid && chatNumber === myLid);
-        if (!isSelfChat) continue;
       }
 
       // Handle !fromMe messages (from other people) based on mode.
@@ -473,6 +505,7 @@ async function startSocket() {
         hasQuotedMessage,
         botIds,
         timestamp: msg.messageTimestamp,
+        fromOwner,
       };
 
       messageQueue.push(event);
@@ -678,9 +711,7 @@ app.post('/send-media', async (req, res) => {
     }
 
     const sent = await sendWithTimeout(chatId, msgPayload);
-
     trackSentMessageId(sent);
-
     res.json({ success: true, messageId: sent?.key?.id });
   } catch (err) {
     res.status(500).json({ error: err.message });
@@ -759,6 +790,9 @@ if (PAIR_ONLY) {
       console.log(`   Set WHATSAPP_ALLOWED_USERS=<phone> to authorize specific users,`);
       console.log(`   or WHATSAPP_ALLOWED_USERS=* for an explicit open bot.`);
     }
+    if (WHATSAPP_MODE === 'bot' && FORWARD_OWNER_MESSAGES) {
+      console.log(`👤 WHATSAPP_FORWARD_OWNER_MESSAGES=true — owner-typed messages will be forwarded with fromOwner:true`);
+    }
     console.log();
     startSocket();
   });

scripts/whatsapp-bridge/outbound_ids.js

@@ -0,0 +1,39 @@
+/**
+ * Bounded LRU set of outbound message IDs.
+ *
+ * Used by the WhatsApp bridge to distinguish "echo of our own /send" from
+ * "owner-typed message on the linked device" when forwarding `fromMe`
+ * inbound events back to the Python adapter.
+ *
+ * Heuristic limitation (intentional, documented for future debugging):
+ * the set is in-memory only.  On bridge restart it is empty, so for the
+ * brief window between restart and the first new outbound, any in-flight
+ * delivery receipts of pre-restart sends would be classified as
+ * owner-typed.  The TTL on owner-driven plugin actions (e.g. handover
+ * sliding TTL) bounds blast radius; persisting would not be worth the
+ * extra complexity / disk churn.
+ */
+
+export function createOutboundIdTracker(maxSize = 512) {
+  const ids = new Set();
+
+  function remember(id) {
+    if (!id) return;
+    ids.add(id);
+    while (ids.size > maxSize) {
+      // Set iteration order is insertion order, so values().next() is the
+      // oldest entry — drop it to keep memory flat under sustained sending.
+      ids.delete(ids.values().next().value);
+    }
+  }
+
+  function has(id) {
+    return Boolean(id) && ids.has(id);
+  }
+
+  function size() {
+    return ids.size;
+  }
+
+  return { remember, has, size };
+}

scripts/whatsapp-bridge/outbound_ids.test.mjs

@@ -0,0 +1,62 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+
+import { createOutboundIdTracker } from './outbound_ids.js';
+
+test('remembers and recognises an outbound id', () => {
+  const tracker = createOutboundIdTracker();
+  tracker.remember('msg-1');
+  assert.equal(tracker.has('msg-1'), true);
+  assert.equal(tracker.has('msg-2'), false);
+});
+
+test('ignores empty / falsy ids', () => {
+  const tracker = createOutboundIdTracker();
+  tracker.remember(undefined);
+  tracker.remember('');
+  tracker.remember(null);
+  assert.equal(tracker.size(), 0);
+  assert.equal(tracker.has(''), false);
+  assert.equal(tracker.has(undefined), false);
+});
+
+test('evicts oldest entry once the cap is exceeded', () => {
+  const tracker = createOutboundIdTracker(3);
+  tracker.remember('a');
+  tracker.remember('b');
+  tracker.remember('c');
+  tracker.remember('d'); // cap=3 → 'a' should be evicted
+  assert.equal(tracker.has('a'), false);
+  assert.equal(tracker.has('b'), true);
+  assert.equal(tracker.has('c'), true);
+  assert.equal(tracker.has('d'), true);
+  assert.equal(tracker.size(), 3);
+});
+
+test('cap holds across many inserts (bounded memory)', () => {
+  const tracker = createOutboundIdTracker(8);
+  for (let i = 0; i < 100; i += 1) {
+    tracker.remember(`id-${i}`);
+  }
+  assert.equal(tracker.size(), 8);
+  // Oldest (id-0..id-91) should be gone, latest 8 retained.
+  assert.equal(tracker.has('id-0'), false);
+  assert.equal(tracker.has('id-91'), false);
+  assert.equal(tracker.has('id-92'), true);
+  assert.equal(tracker.has('id-99'), true);
+});
+
+test('re-remembering an existing id refreshes its position', () => {
+  // Insertion-order semantics: re-adding doesn't move it forward in
+  // Set iteration order. This is intentional — we don't need recency,
+  // just bounded membership.  Pin the actual behaviour so future
+  // refactors don't accidentally introduce LRU semantics.
+  const tracker = createOutboundIdTracker(2);
+  tracker.remember('a');
+  tracker.remember('b');
+  tracker.remember('a'); // no-op for ordering
+  tracker.remember('c'); // evicts 'a' (oldest by insertion)
+  assert.equal(tracker.has('a'), false);
+  assert.equal(tracker.has('b'), true);
+  assert.equal(tracker.has('c'), true);
+});