fix(api): normalize trailing slashes — no slash on param routes

Rule: trailing slash only on collection roots (/). Any route containing
a path parameter {…} uses no trailing slash. Applies across all routers,
scripts, Makefile, and tests. Fixes 307-redirect fragility on POST/PATCH
from naive clients (curl, Codex HTTP calls).

Also adds POST /repos/{slug}/sync — runs ADR-001 consistency check with
--fix via HTTP, so non-MCP agents (Codex) can self-service DB sync without
operator intervention.

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

scripts/register_project.sh

@@ -73,7 +73,7 @@ echo "    API OK"
 
 # ── Step 2: Verify domain exists ───────────────────────────────────────────────
 echo "==> Verifying domain '$DOMAIN' ..."
-DOMAIN_JSON="$(curl -sf "$API_BASE/domains/$DOMAIN/" 2>/dev/null || echo 'NOT_FOUND')"
+DOMAIN_JSON="$(curl -sf "$API_BASE/domains/$DOMAIN" 2>/dev/null || echo 'NOT_FOUND')"
 if [[ "$DOMAIN_JSON" == "NOT_FOUND" ]] || ! echo "$DOMAIN_JSON" | python3 -c "import json,sys; d=json.load(sys.stdin); sys.exit(0 if d.get('slug') else 1)" 2>/dev/null; then
     echo "ERROR: Domain '$DOMAIN' not found in the State Hub."
     echo "  To create: make add-domain DOMAIN=$DOMAIN NAME=\"<display name>\""
@@ -252,7 +252,7 @@ fi
 
 # ── Step 7: Register this machine's local path ────────────────────────────────
 echo "==> Registering host path for $(hostname) ..."
-curl -sf -X POST "$API_BASE/repos/$REPO_SLUG/paths/" \
+curl -sf -X POST "$API_BASE/repos/$REPO_SLUG/paths" \
     -H "Content-Type: application/json" \
     -d "{\"host\": \"$(hostname)\", \"path\": \"$PROJECT_PATH\"}" > /dev/null \
     && echo "    host_paths[$(hostname)] = $PROJECT_PATH"