feat: add prdy-status command and PRD status injection into system prompt

- Add prdy-status.sh for quick one-liner PRD health check (short/json output)
- Inject PRD section count and assumption count into agent system prompt
  so the agent knows PRD state at session start without running validate
- Add status subcommand to mosaic prdy routing and help text

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

bin/mosaic

@@ -56,6 +56,7 @@ PRD:
                          init    Create docs/PRD.md via guided runtime session
                          update  Update existing PRD via guided runtime session
                          validate Check PRD completeness (bash-only)
+                         status  Quick PRD health check (one-liner)
 
 Coordinator (r0):
   coord <subcommand>     Manual coordinator tools
@@ -183,6 +184,40 @@ MISSION_EOF
     fi
   fi
 
+  # Inject PRD status so the agent knows requirements state
+  local prd_file="docs/PRD.md"
+  if [[ -f "$prd_file" ]]; then
+    local prd_sections=0
+    local prd_assumptions=0
+    for entry in "Problem Statement|^#{2,3} .*(problem statement|objective)" \
+                 "Scope / Non-Goals|^#{2,3} .*(scope|non.goal|out of scope|in.scope)" \
+                 "User Stories / Requirements|^#{2,3} .*(user stor|stakeholder|user.*requirement)" \
+                 "Functional Requirements|^#{2,3} .*functional requirement" \
+                 "Non-Functional Requirements|^#{2,3} .*non.functional" \
+                 "Acceptance Criteria|^#{2,3} .*acceptance criteria" \
+                 "Technical Considerations|^#{2,3} .*(technical consideration|constraint|dependenc)" \
+                 "Risks / Open Questions|^#{2,3} .*(risk|open question)" \
+                 "Success Metrics / Testing|^#{2,3} .*(success metric|test|verification)" \
+                 "Milestones / Delivery|^#{2,3} .*(milestone|delivery|scope version)"; do
+      local pattern="${entry#*|}"
+      grep -qiE "$pattern" "$prd_file" 2>/dev/null && prd_sections=$((prd_sections + 1))
+    done
+    prd_assumptions=$(grep -c 'ASSUMPTION:' "$prd_file" 2>/dev/null || echo 0)
+
+    local prd_status="ready"
+    (( prd_sections < 10 )) && prd_status="incomplete ($prd_sections/10 sections)"
+
+    cat <<PRD_EOF
+
+# PRD Status
+
+- **File:** docs/PRD.md
+- **Status:** $prd_status
+- **Assumptions:** $prd_assumptions
+
+PRD_EOF
+  fi
+
   cat <<'EOF'
 # Mosaic Launcher Runtime Contract (Hard Gate)
 
@@ -639,6 +674,9 @@ run_prdy() {
     validate|check)
       MOSAIC_PRDY_RUNTIME="$runtime" exec bash "$tool_dir/prdy-validate.sh" "$@"
       ;;
+    status)
+      exec bash "$tool_dir/prdy-status.sh" "$@"
+      ;;
     help|*)
       cat <<PRDY_USAGE
 mosaic prdy — PRD creation and validation tools
@@ -647,6 +685,7 @@ Commands:
   init [--project <path>] [--name <feature>]   Create docs/PRD.md via guided runtime session
   update [--project <path>]                    Update existing docs/PRD.md via guided runtime session
   validate [--project <path>]                  Check PRD completeness against Mosaic guide (bash-only)
+  status [--project <path>] [--format short|json]  Quick PRD health check (one-liner)
 
 Runtime:
   --claude                    Use Claude runtime (default)

tools/prdy/prdy-status.sh

@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+set -euo pipefail
+#
+# prdy-status.sh — Quick PRD health check (one-liner output)
+#
+# Usage:
+#   prdy-status.sh [--project <path>] [--format short|json]
+#
+# Exit codes:
+#   0 = PRD ready (all required sections present)
+#   1 = PRD incomplete
+#   2 = PRD missing
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/_lib.sh"
+
+# ─── Parse arguments ─────────────────────────────────────────────────────────
+
+PROJECT="."
+FORMAT="short"
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --project) PROJECT="$2"; shift 2 ;;
+    --format)  FORMAT="$2"; shift 2 ;;
+    -h|--help)
+      cat <<'USAGE'
+prdy-status.sh — Quick PRD health check
+
+Usage: prdy-status.sh [--project <path>] [--format short|json]
+
+Options:
+  --project <path>  Project directory (default: CWD)
+  --format <f>      Output format: short (default) or json
+
+Exit codes:
+  0 = PRD ready (all required sections present)
+  1 = PRD incomplete
+  2 = PRD missing
+USAGE
+      exit 0
+      ;;
+    *) echo "Unknown option: $1" >&2; exit 1 ;;
+  esac
+done
+
+PROJECT="${PROJECT/#\~/$HOME}"
+
+# ─── Status check ────────────────────────────────────────────────────────────
+
+PRD_PATH="$(find_prd "$PROJECT")"
+
+if [[ -z "$PRD_PATH" ]]; then
+  if [[ "$FORMAT" == "json" ]]; then
+    echo '{"status":"missing"}'
+  else
+    echo "PRD: missing"
+  fi
+  exit 2
+fi
+
+# Count present sections using the shared manifest
+PRD_CONTENT="$(cat "$PRD_PATH")"
+total=${#PRDY_REQUIRED_SECTIONS[@]}
+present=0
+
+for entry in "${PRDY_REQUIRED_SECTIONS[@]}"; do
+  pattern="${entry#*|}"
+  if echo "$PRD_CONTENT" | grep -qiE "$pattern"; then
+    present=$((present + 1))
+  fi
+done
+
+# Count additional metrics
+fr_count=$(echo "$PRD_CONTENT" | grep -cE '^\- FR-[0-9]+:|^FR-[0-9]+:' || true)
+us_count=$(echo "$PRD_CONTENT" | grep -cE '^#{1,4} US-[0-9]+' || true)
+assumptions=$(echo "$PRD_CONTENT" | grep -c 'ASSUMPTION:' || true)
+
+if (( present == total )); then
+  status="ready"
+  exit_code=0
+else
+  status="incomplete"
+  exit_code=1
+fi
+
+if [[ "$FORMAT" == "json" ]]; then
+  printf '{"status":"%s","sections":%d,"total":%d,"frs":%d,"stories":%d,"assumptions":%d}\n' \
+    "$status" "$present" "$total" "$fr_count" "$us_count" "$assumptions"
+else
+  echo "PRD: $status ($present/$total sections, ${fr_count} FRs, ${us_count} stories, $assumptions assumptions)"
+fi
+
+exit "$exit_code"