feat(ops): deadman switch, model health check, issue filter

Closes #115: bin/deadman-switch.sh -- alerts Telegram when zero commits for 2+ hours
Closes #116: bin/model-health-check.sh -- validates model tags against provider APIs
Closes #117: bin/issue-filter.json + live loop patches -- excludes DO-NOT-CLOSE, EPIC, META, RETRO, INTEL, MORNING REPORT, Rockachopa-assigned issues from agent pickup

All three tested locally:
- deadman-switch correctly detected 14h gap and would alert
- model-health-check parses config.yaml and validates (skips gracefully without API key in env)
- issue filters patched into live claude-loop.sh and gemini-loop.sh

bin/deadman-switch.sh

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+# deadman-switch.sh — Alert when agent loops produce zero commits for 2+ hours
+# Checks Gitea for recent commits. Sends Telegram alert if threshold exceeded.
+# Designed to run as a cron job every 30 minutes.
+
+set -euo pipefail
+
+THRESHOLD_HOURS="${1:-2}"
+THRESHOLD_SECS=$((THRESHOLD_HOURS * 3600))
+LOG_DIR="$HOME/.hermes/logs"
+LOG_FILE="$LOG_DIR/deadman.log"
+GITEA_URL="http://143.198.27.163:3000"
+GITEA_TOKEN=$(cat "$HOME/.hermes/gitea_token_vps" 2>/dev/null || echo "")
+TELEGRAM_TOKEN=$(cat "$HOME/.config/telegram/special_bot" 2>/dev/null || echo "")
+TELEGRAM_CHAT="-1003664764329"
+
+REPOS=(
+  "Timmy_Foundation/timmy-config"
+  "Timmy_Foundation/the-nexus"
+)
+
+mkdir -p "$LOG_DIR"
+
+log() {
+  echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >> "$LOG_FILE"
+}
+
+now=$(date +%s)
+latest_commit_time=0
+
+for repo in "${REPOS[@]}"; do
+  # Get most recent commit timestamp
+  response=$(curl -sf --max-time 10 \
+    -H "Authorization: token ${GITEA_TOKEN}" \
+    "${GITEA_URL}/api/v1/repos/${repo}/commits?limit=1" 2>/dev/null || echo "[]")
+
+  commit_date=$(echo "$response" | python3 -c "
+import json, sys, datetime
+try:
+    commits = json.load(sys.stdin)
+    if commits:
+        ts = commits[0]['created']
+        dt = datetime.datetime.fromisoformat(ts.replace('Z', '+00:00'))
+        print(int(dt.timestamp()))
+    else:
+        print(0)
+except:
+    print(0)
+" 2>/dev/null || echo "0")
+
+  if [ "$commit_date" -gt "$latest_commit_time" ]; then
+    latest_commit_time=$commit_date
+  fi
+done
+
+gap=$((now - latest_commit_time))
+gap_hours=$((gap / 3600))
+gap_mins=$(((gap % 3600) / 60))
+
+if [ "$latest_commit_time" -eq 0 ]; then
+  log "WARN: Could not fetch any commit timestamps. API may be down."
+  exit 0
+fi
+
+if [ "$gap" -gt "$THRESHOLD_SECS" ]; then
+  msg="DEADMAN ALERT: No commits in ${gap_hours}h${gap_mins}m across all repos. Loops may be dead. Last commit: $(date -r "$latest_commit_time" '+%Y-%m-%d %H:%M' 2>/dev/null || echo 'unknown')"
+  log "ALERT: $msg"
+
+  # Send Telegram alert
+  if [ -n "$TELEGRAM_TOKEN" ]; then
+    curl -sf --max-time 10 -X POST \
+      "https://api.telegram.org/bot${TELEGRAM_TOKEN}/sendMessage" \
+      -d "chat_id=${TELEGRAM_CHAT}" \
+      -d "text=${msg}" >/dev/null 2>&1 || true
+  fi
+else
+  log "OK: Last commit ${gap_hours}h${gap_mins}m ago (threshold: ${THRESHOLD_HOURS}h)"
+fi