feat(crunch): add script mode for custom pipeline jobs

crunch script <type> <time> <script.sh> [args...]

Runs any shell script on schedule. Script stdout is piped to talk
for voice output. Empty stdout = silence (no error thrown).

Enables complex multi-step pipelines:
  - Fetch data (basecamp, gh, curl)
  - Write reports to disk
  - Pipe through pi/opencode for AI summarization
  - Final stdout → talk voice notification

Example:
  crunch script daily '08:00' ~/scripts/basecamp-daily.sh

pkgs/crunch/default.nix

@@ -32,6 +32,7 @@
       crunch daily <time> <message>           Recurring daily at time
       crunch weekly <day> <time> <message>    Recurring weekly (Mon or Montag)
       crunch ai <engine> <type> <time> <prompt>  AI crunch (pi|opencode)
+      crunch script <type> <time> <script.sh> [args]  Custom script → talk
       crunch list                              List active jobs
       crunch cancel <name>                     Cancel a job
       crunch purge                             Remove fired one-shot jobs
@@ -45,6 +46,7 @@
       crunch weekly "Montag 09:00" "Weekly review"
       crunch ai pi in "1h" "Fasse neueste Commits zusammen"
       crunch ai opencode daily "08:00" "Review offene Issues"
+      crunch script daily "08:00" ~/scripts/basecamp-daily.sh
       crunch list
       crunch cancel mll-rausbringen-12345
 
@@ -146,6 +148,15 @@
         esac
         exit $?
         ;;
+      _script)
+        script_path="$2"; shift 2
+        rc=0
+        output=$(bash "$script_path" "$@" 2>&1) || rc=$?
+        if [ -n "''${output:-}" ]; then
+          printf '%s' "$output" | "$TALK"
+        fi
+        exit "$rc"
+        ;;
     esac
 
     # ── CLI ───────────────────────────────────────────────────────
@@ -198,6 +209,20 @@
           "$SELF _ai $engine $(printf '%q' "$prompt")" "$name"
         ;;
 
+      # ── Custom script crunch jobs ──
+      script)
+        [ $# -lt 3 ] && { echo "Usage: crunch script <at|in|daily|weekly> <time> <script.sh> [args...]" >&2; exit 1; }
+        sub_type="$1"; time_spec="$2"; script_path="$3"; shift 3
+        script_path="$(readlink -f "$script_path")"
+        [ ! -f "$script_path" ] && { echo "Script not found: $script_path" >&2; exit 1; }
+        name="$(make_name "$(basename "$script_path" .sh)")"
+        exec_cmd="$SELF _script $(printf '%q' "$script_path")"
+        if [ $# -gt 0 ]; then
+          exec_cmd+=" $(printf '%q ' "$@")"
+        fi
+        schedule "$sub_type" "$time_spec" "$exec_cmd" "$name"
+        ;;
+
       # ── Management ──
       list)
         echo "Active crunch jobs:"