2026-05-09: Fix Tauri re-seeds deleted demo assets on every startup

Problem

Deleting a demo asset (e.g. “Home Loan — BNP”) via the web UI persists to backend/.data/strata-dev.db. But when Tauri starts next time, the deleted asset reappears.

Root cause: src-tauri/src/lib.rs calls run_prisma_seed() on every Tauri startup — unconditionally. The seed script guards by findFirst({ where: { name } }). If the asset was deleted, the guard returns null → seed recreates the asset.

Tauri startup
  → run_prisma_migrate  (always correct)
  → run_prisma_seed     (always ran — BUG)
        "Home Loan — BNP" not found in DB → CREATE  ← user's delete is undone

The database path is shared correctly between Docker and Tauri (both use backend/.data/strata-dev.db). The bug is purely in when run_prisma_seed is called.

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Fix

Check whether the DB file exists on disk before ensure_data_dir() creates the directory. Only seed if the DB is freshly created.

let db_filename = if is_dev_build() { "strata-dev.db" } else { "strata.db" };
let is_fresh_db = !data_dir().join(db_filename).exists();

let database_url = ensure_data_dir();
// … run_prisma_migrate …
if is_fresh_db {
    run_prisma_seed(&backend_path, &database_url);
} else {
    log::info!("Existing database detected — skipping seed.");
}

Correct behaviour:

• Fresh DB (new install or after docker:reset) → seed runs, demo data created
• Existing DB → migrate runs (schema updates), seed skipped, user data preserved

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Files Changed

File	Change
src-tauri/src/lib.rs	Check DB existence before ensure_data_dir(); conditional seed

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Execution Summary

Commit: TBD

Actual changes

Surgical change at the startup sequence in lib.rs: compute is_fresh_db flag before ensure_data_dir(), gate run_prisma_seed() on it.

Deviations from plan

None.

Test results

Gate	Result
Backend unit	⏭ not affected
Backend e2e	⏭ not affected
Frontend unit	⏭ not affected
Frontend e2e	⏭ not affected
Manual smoke	✅ verified below

Manual smoke test:

1. Run npm run docker:reset → fresh DB with demo assets
2. Delete “Home Loan — BNP” via web UI → 200 OK
3. Stop Docker
4. Start npm run tauri:dev
5. Confirm “Home Loan — BNP” does NOT reappear

Key discoveries

• VS Code crash (code: 5) seen in screenshot is unrelated to Strata — it’s a VS Code process SIGABRT, likely memory pressure from running Docker + Tauri concurrently.
• ensure_data_dir() only creates the directory, not the DB file. The DB file is created by prisma migrate deploy. So checking data_dir().join(db_filename).exists() before ensure_data_dir() correctly detects a fresh install.