Add capture mode: /capture + per-room capture threads → cross-project inbox

A capture-thread message (or /capture <text> in any room) logs to standards/
INBOX.md via capture-note.sh — deterministic, no claude call — and confirms
in-thread; /triage stays the gate into each repo (D13). Thread roots seeded by
seed-capture-threads.py.

scripts/capture-note.sh

@@ -0,0 +1,45 @@
+#!/bin/zsh -l
+# capture-note.sh — matrix-bridge capture wrapper.
+#
+# Invoked over SSH by the bot:  capture-note.sh <project> <text...>
+# Appends ONE line to the cross-project inbox (standards/INBOX.md) in the exact format the
+# /capture skill uses, commits it, and best-effort pushes — so /triage (run later inside the
+# target repo) drains it like any other captured item.
+#
+# Deterministic on purpose: no LLM, no token, nothing leaves the Mac except the git push to
+# Gitea. The "smarts" (real type/priority, repo-routing, phrasing) stay at /triage, where the
+# human is — and routing message text through a frontier model would break the sovereignty
+# boundary (D13/D8). Defaults every capture to a raw [idea][P2]; /triage reclassifies.
+#
+# Why a login shell (-l): git config / PATH live in ~/.zprofile, which a non-login SSH shell
+# skips — the same seam as launch-claude.sh / ask-claude.sh.
+
+set -e
+
+standards="$HOME/Projects/standards"
+inbox="$standards/INBOX.md"
+
+project="$1"
+shift || true
+note="$*"
+
+if [[ -z "$project" || -z "$note" ]]; then
+  print -u2 "usage: capture-note.sh <project> <text>"
+  exit 2
+fi
+if [[ ! -f "$inbox" ]]; then
+  print -u2 "capture-note: inbox not found: $inbox"
+  exit 1
+fi
+
+line="- [ ] ($project) [idea][P2] $note — via matrix, $(date +%F)"
+
+print -r -- "$line" >> "$inbox"
+
+git -C "$standards" add INBOX.md
+git -C "$standards" commit -q -m "Capture: ${note[1,60]} (via matrix)" -- INBOX.md
+# Push is best-effort — a captured line committed locally is not lost if Gitea is unreachable.
+git -C "$standards" push -q 2>/dev/null || print -u2 "capture-note: push skipped/failed (committed locally)"
+
+# Echo the exact line so the bot can post it back into the thread as confirmation.
+print -r -- "$line"