chore: add SKIP_MIN_VERSION_CHECK env var and database URL docs

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -51,10 +51,15 @@ After making code changes, you MUST run the appropriate checks and fix all error
 
 `backend/summarized_schema.txt` provides a compact overview of all tables, columns, types, ENUMs, and foreign keys. Use it to quickly understand the data model and relationships. Note: this file is a simplified summary — it omits indexes, constraints details, and other metadata.
 
-For exact table definitions (indexes, constraints, column defaults, etc.), query the database directly:
+For exact table definitions (indexes, constraints, column defaults, etc.), query the database directly.
+
+**IMPORTANT**: The database name varies per worktree/branch. Always read `.env.local` first to get the correct `DATABASE_URL`. The default `windmill` database is only used on the main branch — worktrees use branch-specific database names (e.g., `windmill_add_fast_filter`). Using the wrong database means your queries, inserts, and migrations will target stale or empty data.
 
 ```bash
-psql postgres://postgres:changeme@localhost:5432/windmill
+# Always check .env.local first:
+grep DATABASE_URL .env.local
+# Then use the correct database URL, e.g.:
+psql "postgres://postgres:changeme@127.0.0.1:5432/windmill_add_fast_filter"
 ```
 
 Useful psql commands:

backend/windmill-api/src/live_migrations.rs

@@ -101,12 +101,21 @@ async fn fast_filter_migration(db: &DB) -> Result<(), Error> {
 
 async fn fast_filter_migration_inner(db: &DB) -> Result<(), Error> {
     // Wait until all workers are at least version 1.647 so new jobs write fast_filter
-    loop {
-        if MIN_VERSION_IS_AT_LEAST_1_647.met().await {
-            break;
+    let skip_version_check = std::env::var("SKIP_MIN_VERSION_CHECK")
+        .map(|v| v == "1" || v == "true")
+        .unwrap_or(false);
+    if !skip_version_check {
+        loop {
+            if MIN_VERSION_IS_AT_LEAST_1_647.met().await {
+                break;
+            }
+            tracing::info!("fast_filter migration: waiting for all workers to be >= 1.647");
+            tokio::time::sleep(std::time::Duration::from_secs(30)).await;
         }
-        tracing::info!("fast_filter migration: waiting for all workers to be >= 1.647");
-        tokio::time::sleep(std::time::Duration::from_secs(30)).await;
+    } else {
+        tracing::info!(
+            "fast_filter migration: skipping version check (SKIP_MIN_VERSION_CHECK=true)"
+        );
     }
 
     // Backfill existing rows in batches (skip skipped jobs — they stay NULL)