feat: add multi-runtime support (coord run, prdy --codex) and next-task capsule

- coord/prdy subcommands now accept --claude/--codex runtime flags
- New `mosaic coord run` generates continuation context and launches
  selected runtime, replacing manual copy/paste workflow
- Next-task capsule (.mosaic/orchestrator/next-task.json) provides
  machine-readable execution context for deterministic session launches
- Codex strict orchestrator profile added to runtime/codex/RUNTIME.md
- Orchestrator protocol updated with between-session run flow
- New smoke-test.sh for orchestration behavior verification

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

tools/orchestrator/smoke-test.sh

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+set -euo pipefail
+#
+# smoke-test.sh — Behavior smoke checks for coord continue/run workflows.
+#
+# Usage:
+#   smoke-test.sh
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/_lib.sh"
+
+PASS=0
+FAIL=0
+
+pass_case() {
+  echo "PASS: $1"
+  PASS=$((PASS + 1))
+}
+
+fail_case() {
+  echo "FAIL: $1" >&2
+  FAIL=$((FAIL + 1))
+}
+
+tmp_project="$(mktemp -d)"
+trap 'rm -rf "$tmp_project"' EXIT
+
+mkdir -p "$tmp_project/.mosaic/orchestrator" "$tmp_project/docs/scratchpads"
+
+cat > "$tmp_project/.mosaic/orchestrator/mission.json" <<'JSON'
+{
+  "mission_id": "smoke-mission-20260223",
+  "name": "Smoke Mission",
+  "status": "active",
+  "project_path": "SMOKE_PROJECT",
+  "quality_gates": "pnpm lint && pnpm test",
+  "milestones": [
+    { "id": "M1", "name": "Milestone One", "status": "pending" }
+  ],
+  "sessions": []
+}
+JSON
+
+cat > "$tmp_project/docs/MISSION-MANIFEST.md" <<'MD'
+# Mission Manifest
+MD
+
+cat > "$tmp_project/docs/scratchpads/smoke-mission-20260223.md" <<'MD'
+# Scratchpad
+MD
+
+cat > "$tmp_project/docs/TASKS.md" <<'MD'
+| id | status | milestone | description | pr | notes |
+|----|--------|-----------|-------------|----|-------|
+| T-001 | pending | M1 | Smoke task | | |
+MD
+
+codex_continue_output="$(MOSAIC_COORD_RUNTIME=codex bash "$SCRIPT_DIR/continue-prompt.sh" --project "$tmp_project")"
+capsule_file="$tmp_project/.mosaic/orchestrator/next-task.json"
+
+if [[ -f "$capsule_file" ]]; then pass_case "continue writes next-task capsule"; else fail_case "continue writes next-task capsule"; fi
+if jq -e '.runtime == "codex"' "$capsule_file" >/dev/null 2>&1; then pass_case "capsule runtime is codex"; else fail_case "capsule runtime is codex"; fi
+if jq -e '.next_task == "T-001"' "$capsule_file" >/dev/null 2>&1; then pass_case "capsule next_task is T-001"; else fail_case "capsule next_task is T-001"; fi
+if grep -Fq 'Target runtime:** codex' <<< "$codex_continue_output"; then pass_case "continue prompt contains target runtime codex"; else fail_case "continue prompt contains target runtime codex"; fi
+
+codex_run_prompt="$(MOSAIC_COORD_RUNTIME=codex bash "$SCRIPT_DIR/session-run.sh" --project "$tmp_project" --print)"
+if [[ "$(printf '%s\n' "$codex_run_prompt" | head -n1)" == "Now initiating Orchestrator mode..." ]]; then pass_case "codex run prompt first line is mode declaration"; else fail_case "codex run prompt first line is mode declaration"; fi
+if grep -Fq 'Do NOT ask clarifying questions before your first tool actions' <<< "$codex_run_prompt"; then pass_case "codex run prompt includes no-questions hard gate"; else fail_case "codex run prompt includes no-questions hard gate"; fi
+if grep -Fq '"next_task": "T-001"' <<< "$codex_run_prompt"; then pass_case "codex run prompt embeds capsule json"; else fail_case "codex run prompt embeds capsule json"; fi
+
+claude_run_prompt="$(MOSAIC_COORD_RUNTIME=claude bash "$SCRIPT_DIR/session-run.sh" --project "$tmp_project" --print)"
+if [[ "$(printf '%s\n' "$claude_run_prompt" | head -n1)" == "## Continuation Mission" ]]; then pass_case "claude run prompt remains continuation prompt format"; else fail_case "claude run prompt remains continuation prompt format"; fi
+
+echo ""
+echo "Smoke test summary: pass=$PASS fail=$FAIL"
+if (( FAIL > 0 )); then
+  exit 1
+fi