feat(discord): writes on write-marked roots, web fetch and search, held prompts (#1509)

Row 23. write_file and edit_file for roots marked write: true under the
same fence as reads; web_fetch (https only, public addresses, pinned
connection, capped body) and web_search through SearXNG; extension
renamed to tools.mjs. Engine holds a prompt while pi is busy and sends
it as its own run, so a second message mid-turn no longer folds into
the first (live defect). fake-pi models the real follow-up folding.

Suite 52/52, node tests 129. rev-code-02 APPROVED round 3, comment
26362, tree dbd2ce9a. Records: QUEUE rows 23-24, CURRENT, BUILD-LOG
phase, SESSIONS, row 24 brief (git verbs, D5-D7 ruled).

Co-Authored-By: Claude Fable 5.1 <[email protected]>

docs/TOOLS.md

@@ -182,9 +182,14 @@ user entry may carry `channels`, an allowlist of listed channel ids.
 unit `[email protected]` (one instance per binding, restart on
 failure, exit 3 never retried, SIGTERM on `systemctl --user stop`, SIGHUP on
 `systemctl --user reload`). An optional `tools` key in the binding declares
-read-only roots; pi then runs with its own tools off and the package's
+file roots; pi then runs with its own tools off and the package's
 extension providing `list_dir`, `read_file` and `search` confined to those
-roots, with each call in the turn record. `tools` is a fixed key: changing
+roots, plus `write_file` and `edit_file` for roots marked `"write": true`
+(temp file and rename, no folder creation, no dot-prefixed path, no
+credential shapes), and `web_fetch` and `web_search` when `tools.web`
+names a SearXNG instance (https only, public addresses only, three
+redirects, capped body, html to text), with each call in the turn record.
+Sage has no git; the operator commits from the terminal. `tools` is a fixed key: changing
 it needs a stop and start. Records
 under `<dataRoot>/discord/<binding>/`: `inbox.jsonl`, `outbox.jsonl`,
 `drops.jsonl`, `admissions.jsonl`, `notices.jsonl`, `reloads.jsonl`, write-once `turns/<id>.json`. Suite: