feat: add group chat activation mode

docs/group-messages.md

@@ -8,13 +8,13 @@ read_when:
 Goal: let Clawd sit in WhatsApp groups, wake up only when pinged, and keep that thread separate from the personal DM session.
 
 ## What’s implemented (2025-12-03)
-- Mentions required by default: real WhatsApp @-mentions (via `mentionedJids`), regex patterns, or the bot’s E.164 anywhere in the text all count.
+- Activation modes: `mention` (default) or `always`. `mention` requires a ping (real WhatsApp @-mentions via `mentionedJids`, regex patterns, or the bot’s E.164 anywhere in the text). `always` wakes the agent on every message but it should reply only when it can add meaningful value; otherwise it returns the silent token (see below).
 - Group allowlist bypass: we still enforce `allowFrom` on the participant at inbox ingest, but group JIDs themselves no longer block replies.
 - Per-group sessions: session keys look like `group:<jid>` so commands such as `/verbose on` or `/think:high` are scoped to that group; personal DM state is untouched. Heartbeats are skipped for group threads.
 - Context injection: last N (default 50) group messages are prefixed under `[Chat messages since your last reply - for context]`, with the triggering line under `[Current message - respond to this]`.
 - Sender surfacing: every group batch now ends with `[from: Sender Name (+E164)]` so Pi knows who is speaking.
 - Ephemeral/view-once: we unwrap those before extracting text/mentions, so pings inside them still trigger.
-- New session primer: on the first turn of a group session we now prepend a short blurb to the model like `You are replying inside the WhatsApp group "<subject>". Group members: +44..., +43..., … Address the specific sender noted in the message context.` If metadata isn’t available we still tell the agent it’s a group chat.
+- New session primer: on the first turn of a group session we now prepend a short blurb to the model like `You are replying inside the WhatsApp group "<subject>". Group members: Alice (+44...), Bob (+43...), … Activation: trigger-only … Address the specific sender noted in the message context.` If metadata isn’t available we still tell the agent it’s a group chat.
 
 ## Config for Clawd UK (+447700900123)
 Add a `groupChat` block to `~/.clawdis/clawdis.json` so display-name pings work even when WhatsApp strips the visual `@` in the text body:
@@ -23,7 +23,7 @@ Add a `groupChat` block to `~/.clawdis/clawdis.json` so display-name pings work
 {
   "inbound": {
     "groupChat": {
-      "requireMention": true,
+      "activation": "mention",
       "historyLimit": 50,
       "mentionPatterns": [
         "@?clawd",
@@ -40,6 +40,10 @@ Notes:
 - The regexes are case-insensitive; they cover `@clawd`, `@clawd uk`, `clawdbot`, and the raw number with or without `+`/spaces.
 - WhatsApp still sends canonical mentions via `mentionedJids` when someone taps the contact, so the number fallback is rarely needed but is a good safety net.
 
+### Always-on mode
+
+Set `"activation": "always"` to wake on every group message. In this mode the agent is instructed to return `NO_REPLY` (exact token) when it decides no reply is necessary, and Clawdis will suppress the outbound message.
+
 ## How to use
 1) Add Clawd UK (`+447700900123`) to the group.
 2) Say `@clawd …` (or `@clawd uk`, `@clawdbot`, or include the number). Anyone in the group can trigger it.