Chatzotzrot: silver trumpets with BEAM routing, subscription, and zikaron

Bamidbar 10:2 — Aseh lekha shtei chatzotz'rot kesef, mikshah ta'aseh otam.
Two trumpets, hammered from a single piece. Five signals, five patterns.

- Upgraded from simple function module to GenServer with state
- Recipient routing: :all (assembly_all, breaking_camp, moadim),
  :kohanim (assembly_leaders, war), :operators (war)
- PubSub via BEAM messaging: subscribe/1, unsubscribe/1
  Signals delivered as {:chatzotzrot, record} messages
- Zikaron (remembrance — Bamidbar 10:10): signal history with
  type filtering and limit. V'hayu lakhem l'zikaron.
- Dead subscriber cleanup via Process.monitor/1
- Added to supervision tree in application.ex
- 30 new tests: patterns, urgency, routing, subscription,
  zikaron history, dead process cleanup, format compliance
- All 125 Elixir tests pass, 0 failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

vav_pipeline/lib/vav_pipeline/application.ex

@@ -4,6 +4,7 @@ defmodule VavPipeline.Application do
 
   Starts the supervision tree with:
   - Repo (L3 PostgreSQL — oral tradition persistence)
+  - Chatzotzrot (silver trumpets — signal system)
   - ShabbatTimer (mandatory cessation monitor)
   - ShoreshEnginePort (Erlang Port to Haskell engine, if binary found)
   - TalmudicEngineSocket (Unix socket to Prolog engine)
@@ -25,6 +26,7 @@ defmodule VavPipeline.Application do
 
     children =
       [
+        {VavPipeline.Chatzotzrot, []},
         {VavPipeline.ShabbatTimer, []}
       ]
       |> maybe_add_repo()