feat(signal): page-signal CLI wrapper + workflows + cross-project broadcast helper

Three coupled additions ship together.

claude-templates/bin/page-signal is a bash wrapper around signal-cli
send. It defaults to --note-to-self for safety. The wrapper supports
--file for attachments, --to <+number> for outbound (explicit per
call, no defaults, no batch), --quiet, and --json. Exit codes: 0
sent, 1 signal-cli failure, 2 usage error, 3 signal-cli not
installed.

claude-templates/.ai/workflows/page-signal.org carries the
discrimination rules and safety rails. When desktop notify covers it,
don't reach for Signal. Long-running task completion is the canonical
case. Outbound to other contacts requires explicit Craig instruction
per send. A known-limitation note covers the current notification
gap. signal-cli registered on Craig's primary number means messages
don't fire notifications until the pending Google Voice registration
lands.

claude-templates/.ai/workflows/cross-project-broadcast.org and its
helper cross-project-broadcast.py fan out a single message file to
every AI project's inbox in one operation. Discovery is
fingerprint-based: any directory under ~/code, ~/projects, ~/.emacs.d
with both .ai/protocols.org and a top-level inbox/ is broadcastable.
Senders are auto-excluded. Verified discovery against 23
broadcastable targets.

Makefile's install target gains a general bin/ loop. The previous
version hardcoded bin/ai. The new version iterates over every
executable under claude-templates/bin/ and symlinks each into
~/.local/bin/. install-hooks (existing Claude hook installer) is
unchanged. install-githooks (sync-check pre-commit hook setup, added
earlier today) is unchanged. The bin/ loop now picks up bin/page-signal
automatically.

INDEX entries for both new workflows landed under Tools and meta.

No bats tests on the new scripts. page-signal was smoke-tested with a
live send. The send succeeded. The notification gap is covered by the
workflow's known-limitation note. cross-project-broadcast.py was
smoke-tested via --list against the live project set. Tests can be
added when the broadcast pattern proves out across multiple use cases.

1 files changed, 4 insertions, 0 deletions

diff --git a/.ai/workflows/INDEX.org b/.ai/workflows/INDEX.org
index 17c99cb..aa64e2e 100644
--- a/.ai/workflows/INDEX.org
+++ b/.ai/workflows/INDEX.org
@@ -80,6 +80,10 @@ This index must list every =.org= file in =.ai/workflows/= except this one and e
 
 - =process-meeting-transcript.org= — record → transcript → labeled archive.
   - Triggers: "process the transcript", "process the recording". Auto: new files in =~/sync/recordings/=.
+- =page-signal.org= — send Craig a Signal message via =page-signal= when desktop notifications won't reach him. Defaults to note-to-self. Outbound to other contacts requires explicit =--to <+number>= every call. Auto: long-running task completion, cross-device deliverables, operator-attention events. NOT for routine completions or periodic status pings.
+  - Triggers: "page me on signal", "signal me when X is done", "send a signal note about X"
+- =cross-project-broadcast.org= — fan out a single message to every AI project's inbox via the discovery helper =cross-project-broadcast.py= + the existing =inbox-send.py=. Use sparingly for capability announcements and shared rule changes; not for project-specific handoffs.
+  - Triggers: "broadcast this to every project", "notify every project about X", "fan out this announcement", "let every project know X is available"
 - =page-me.org= — set a timed notification.
   - Triggers: anything containing the word "page" used as a verb ("page me", "page me in 10 minutes", "page me at 3pm")
 - =status-check.org= — proactive long-running-job updates.