fix(context): sync to the estate canonical context-sync.sh (ADR-0019)

Caught by the new estate-wide context-sync-drift gate (infra, ADR-0019).
This repo's copy had diverged from the canonical established in dma-cli/
infra -- synced to it, dead Cursor/Aider artifacts removed (2026-09-01
harness decision), Taskfile's drift assertion narrowed to match, adapters
regenerated against the current canonical AGENT.md.

Changed:
M  .context/system-prompt.txt
M  AGENTS.md
M  scripts/context-sync.sh

Refs: ADR-0019 (infra)

scripts/context-sync.sh

@@ -5,15 +5,29 @@
 # For Claude Code: generates project-only CLAUDE.md (it inherits root via tree walk)
 # For everything else: concatenates root AGENT.md + project PROJECT.md
 #
-# Usage: ./scripts/context-sync.sh [adapter...]
+# Cursor and Aider adapters removed 2026-09-01 — neither is a supported harness
+# any more. Supported: Claude Code, Antigravity, OpenCode, Mistral Vibe, Crush,
+# Pi. All read CLAUDE.md or AGENTS.md; system-prompt.txt remains for Open WebUI,
+# Mods and raw API use.
+#
+# Usage: ./scripts/context-sync.sh [--force] [adapter...]
 # Task:  task context:sync
 #
 # Override root context: ROOT_CONTEXT=~/dev/.context/AGENT.md ./scripts/context-sync.sh
 
 set -euo pipefail
 
+# Parse --force flag and collect adapter names separately
+FORCE=false
+ADAPTERS=()
+for _arg in "$@"; do
+  case "$_arg" in
+    --force) FORCE=true ;;
+    *) ADAPTERS+=("$_arg") ;;
+  esac
+done
+
 PROJECT_FILE=".context/PROJECT.md"
-SKILLS_DIR=".skills"
 
 # Walk up to find root .context/AGENT.md
 find_root_context() {
@@ -36,19 +50,28 @@ if [ ! -f "$PROJECT_FILE" ]; then
   exit 1
 fi
 
+# Pre-flight: reject unfilled {{...}} placeholders unless --force
+if [ "$FORCE" = false ]; then
+  _placeholders=$(grep -n '{{[^}]*}}' "$PROJECT_FILE" 2>/dev/null || true)
+  if [ -n "$_placeholders" ]; then
+    echo "Error: unfilled placeholders in $PROJECT_FILE:" >&2
+    while IFS= read -r _match; do
+      _lineno="${_match%%:*}"
+      _content="${_match#*:}"
+      _token=$(printf '%s' "$_content" | grep -o '{{[^}]*}}' | head -1)
+      echo "  $PROJECT_FILE:$_lineno: unfilled placeholder $_token" >&2
+    done <<< "$_placeholders"
+    echo "" >&2
+    echo "Fill these placeholders, then re-run: task context:sync" >&2
+    echo "To bypass validation: bash scripts/context-sync.sh --force" >&2
+    exit 1
+  fi
+fi
+
 if [ -n "$ROOT_CONTEXT" ] && [ -f "$ROOT_CONTEXT" ]; then
   echo "  Root context: $ROOT_CONTEXT"
 else
-  # No reachable root AGENT.md — common in CI's clean checkout. The root+project
-  # adapters (AGENTS.md, system-prompt.txt) require the root context to
-  # regenerate correctly, so we skip them entirely and only regenerate CLAUDE.md
-  # (which is project-only and inherits root via tree walk in Claude Code itself).
-  echo "  No root AGENT.md found — regenerating CLAUDE.md only"
-  echo "Syncing project context from $PROJECT_FILE..."
-  cat "$PROJECT_FILE" > CLAUDE.md
-  echo "  → CLAUDE.md (project-only)"
-  echo "Done."
-  exit 0
+  echo "  No root AGENT.md found (project context only)"
 fi
 
 # Emit root context + separator
@@ -95,6 +118,7 @@ generate_system_prompt() {
 
 # ── MCP config ───────────────────────────────────────────────
 generate_mcp() {
+  # Ensure baseline file exists with project-specific knowledge server
   if [ ! -f .context/mcp.json ]; then
     cat > .context/mcp.json << 'JSON'
 {
@@ -106,27 +130,47 @@ generate_mcp() {
   }
 }
 JSON
-    echo "  → .context/mcp.json (new)"
-  else
-    echo "  → .context/mcp.json (exists, skipped)"
   fi
+
+  # Merge root mcp-servers.json if found alongside root AGENT.md
+  local root_mcp=""
+  if [ -n "$ROOT_CONTEXT" ] && [ -f "$ROOT_CONTEXT" ]; then
+    local candidate
+    candidate="$(dirname "$ROOT_CONTEXT")/mcp-servers.json"
+    [ -f "$candidate" ] && root_mcp="$candidate"
+  fi
+
+  if [ -z "$root_mcp" ]; then
+    echo "  → .context/mcp.json (exists, no root mcp-servers.json found)"
+    return
+  fi
+
+  # Root servers take precedence over project entries on key conflict
+  local root_servers count updated
+  root_servers=$(jq '.servers' "$root_mcp")
+  count=$(printf '%s' "$root_servers" | jq 'keys | length')
+  updated=$(jq --argjson root "$root_servers" \
+    '.mcpServers = (.mcpServers + $root)' \
+    .context/mcp.json)
+  printf '%s\n' "$updated" > .context/mcp.json
+  echo "  → .context/mcp.json (merged $count root servers)"
 }
 
 echo "Syncing project context from $PROJECT_FILE..."
 
-if [ $# -eq 0 ]; then
+if [ ${#ADAPTERS[@]} -eq 0 ]; then
   generate_claude
   generate_agents
   generate_system_prompt
   generate_mcp
 else
-  for adapter in "$@"; do
+  for adapter in "${ADAPTERS[@]}"; do
     case "$adapter" in
       claude)  generate_claude ;;
       agents)  generate_agents ;;
       prompt|system|openwebui|owui|generic) generate_system_prompt ;;
       mcp)     generate_mcp ;;
-      *) echo "Unknown adapter: $adapter" ;;
+      *) echo "Unknown adapter: $adapter" >&2; exit 1 ;;
     esac
   done
 fi