From bf26175724c23efe4d2a2387ce2cfe153a609c3c Mon Sep 17 00:00:00 2001
From: Maurice <mauriceboe@icloud.com>
Date: Tue, 13 Oct 2026 21:10:41 +0200
Subject: [PATCH] docs(server): say which builds refuse a migrated database and
 which do not

The pre-migrate snapshot docstring said an older release refuses a database a newer TREK migrated. Only images from 5.0 on do; 4.3.x and earlier start on it without a warning. server/CLAUDE.md said anything the legacy baseline cannot map refuses the boot, which holds only above step 258.
---
 server/CLAUDE.md                      |  2 +-
 server/src/db/pre-migrate-snapshot.ts | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/server/CLAUDE.md b/server/CLAUDE.md
index 7750eeb2e..6de4ca3e3 100644
--- a/server/CLAUDE.md
+++ b/server/CLAUDE.md
@@ -75,7 +75,7 @@ Nest owns everything. Every domain is a DI module under `src/nest/<domain>/` (`c
 - **Scheduling**: `src/nest/scheduling/` (`CronRegistrarService`) is the one way to schedule a cron. Jobs are `*.job.ts` providers in their owning domain. The registrar refuses to schedule under `NODE_ENV=test` (an integration test pins it). **Never use a `@Cron` decorator**: it bypasses that gate. Every tick first takes the job's row in `scheduler_leases` (`SchedulerLeasesRepository.acquire`, one conditional upsert that decides the race), renews it while it runs and keeps it for a short settle window afterwards, so two processes on one database never run the same tick; a job needs nothing of its own for this. Claims on individual rows (the reminder jobs' `claimReminder`) stay where they are: the lease decides who runs a tick, the claim what a tick may send.
 - **Plugins** (`src/nest/plugins/`): the child-process runtime (`supervisor/`, `runtime/plugin-host-entry.ts`, `protocol/envelope.ts`) is **intentionally not Nest**; it is the security boundary. `host/rpc-host.ts` registers an RPC method at spawn only if the plugin holds the unlocking permission (registration = authorization). Install-time gates live in `install/`; the manifest's `trek` version range fails closed, and `TREK_PLUGINS_IGNORE_TREK_RANGE` downgrades that to a warning. The protocol tables in `protocol/envelope.ts` (+ `src/plugin-event-sink.ts`) are **generated** into `plugin-sdk/` and `shared/`: run `gen:plugin-facts` after touching them and commit the output. What a plugin gets back is `protocol/output-contract.ts`: every wire method has an entry, and an entity result (`trips.getById`, `todos.list`, `vacay.mine`, ...) is cut down to its published fields in `rpc-host.ts` on the way out, together with every child row it carries whose field is listed in `PLUGIN_ENTITY_NESTED` (a day's `notes_items`, a reservation's `endpoints`). A new column on any whole-row table behind those entities, child tables included, fails `tests/unit/plugins/output-contract.schema.test.ts` until it is listed as published or withheld (the SDK's `PLUGIN_ENTITY_FIELDS` and `PLUGIN_ENTITY_NESTED` are generated from it); a method left as `readModel` must return a value built field by field from named columns. A plugin's own SQL (`host/plugin-data.service.ts`) is held to a row cap, and `query`, `tx` and an `exec` script to a time budget checked between rows and statements (`migrate` is deliberately not timed). `runtime/egress-policy.ts` is a hand-kept mirror guarded by a parity test in `plugin-sdk/`; change both sides together.
 - **Storage**: `src/nest/storage/` is the upload driver abstraction (local / S3 / mirror behind one interface, with an admin surface and a usage job). Domain services never touch the filesystem or the S3 SDK directly. Where the data lives (`data/`, `uploads/`, backups, logs, key files, the DB file) is resolved in one place, `src/app-config/data-paths.ts`; a provider that reads one injects `DataPathsService`, plain helper modules shared with code outside the container call `resolveDataPaths()` (the list is in `src/app-config/README.md`), and nothing anchors a data path on its own `__dirname` or on `process.cwd()`.
-- **DB** (`src/db/`): `better-sqlite3`, WAL, FK on. `database.ts` only holds the connection and applies pragmas. It does not build a schema, and importing it opens nothing (the first reader does). The connection's lifecycle belongs to the `DatabaseLifecycle` provider (`nest/database/database-lifecycle.service.ts`): `buildApp()` opens it through `open()` (which binds the ORM to later swaps and runs the schema bootstrap below), the shutdown closes it through `close()`, and a restore or the demo reset swaps the file only through the database backup port, `DATABASE_BACKUP` (`nest/database/database-backup.interface.ts`; the SQLite implementation is `nest/backup/sqlite-database-backup.ts`: `VACUUM INTO` snapshot, close, atomic file swap, `reopen()`). The port works on `DatabaseLifecycle.file`, the one resolved path (`TREK_DB_FILE` or `data/travel.db`), and a snapshot that fails fails the backup rather than archiving the live file. `MaintenanceRepository` is provided only by `MaintenanceModule`'s factory and injected everywhere else; no consumer constructs it. A provider that has to follow every reopen (the demo reset job saves the first demo baseline after a restore's re-bootstrap seeded the example trips) registers with `DatabaseLifecycle.onReopened()`, which runs after the reopen's schema bootstrap; a listener contains its own failures, since one that throws fails the reopen. MikroORM's migrations (`db/migrations/`) are the only schema source, **including for tests**: the hand-kept `schema.ts`/`migrations.ts`/`seeds.ts` builders and the parity test that guarded them are gone. Seeding is the MikroORM seeders in `db/seeders/`, applied by `db/orm.ts` from `buildApp()` before anything reads. An install the retired positional runner migrated (a `schema_version` row, no `mikro_orm_migrations` rows) is baselined by `db/legacy-baseline.ts`: the migrations whose `Legacy migration step N` docstring is ≤ its version are recorded as executed (never replayed) in the same transaction as the migrator run, while the baseline migration itself still runs first, as the legacy runner's `createTables()` did on every boot; anything it cannot map refuses the boot. Before a boot applies pending migrations to a file database that holds anything, `db/pre-migrate-snapshot.ts` writes a `VACUUM INTO` copy next to it (`pre-migrate-<schema>-<time>.db`, `<schema>` being `legacy-<schema_version>` or the last recorded migration's timestamp; the newest `TREK_DB_PRE_MIGRATE_SNAPSHOT_KEEP` stay) and the newer-database refusal names the matching copy; a copy that cannot be written refuses the boot unless `TREK_DB_PRE_MIGRATE_SNAPSHOT=false`. It is off under `NODE_ENV=test` unless a suite sets that variable to true, and a restore's re-bootstrap skips it (the archive is the copy). After the migrator, `db/email-case-index.ts` creates the case-insensitive unique index on `users.email` that its migration had to defer on an install holding two accounts whose emails differ only in case (flag `email_case_index_pending`). `db/orm-driver.ts` binds the ORM to that same connection instead of opening a second one — with `:memory:` under test, a second connection is a second, empty database. Kysely statements (`this.kysely<...>()`) type against `DB` from `db/kysely/db.ts`, narrowed with `Pick<DB, 'trips' | 'days'>`; those files are generated from the migrated schema by `scripts/generate-db-types.ts`, so a migration that adds or changes a column is followed by `npm run gen:db-types`, never by a hand-written table interface. Every read and write goes through a repository in `db/repositories/` (each extends the shared `TrekRepository` base in `db/repositories/_shared/`, which validates the request context before delegating to MikroORM) and, for multi-statement writes, `UnitOfWork.transactional(...)` (`nest/database/unit-of-work.ts`, provided by the global `OrmModule`) — there is no `DatabaseService`/`DatabaseModule` to inject any more. Entrypoints outside an HTTP request — an MCP tool call, a plugin RPC dispatch, a WebSocket message, a cron job, boot-time seeding, a backup restore — open one explicitly with `withRequestContext()` (`nest/database/request-context.ts`), since only the pathless `mikroOrmRequestContext` middleware `buildApp()` mounts (with `@mikro-orm/nestjs`'s own `registerRequestContext` turned off in `app.module.ts`, UPLOADS-P16) forks an `EntityManager` per HTTP request. `NODE_ENV=test` ⇒ isolated `:memory:` DB per vitest worker, opened from a snapshot `tests/global-setup.ts` migrates once per run; `TREK_DB_FILE` ⇒ explicit file DB (Playwright harness).
+- **DB** (`src/db/`): `better-sqlite3`, WAL, FK on. `database.ts` only holds the connection and applies pragmas. It does not build a schema, and importing it opens nothing (the first reader does). The connection's lifecycle belongs to the `DatabaseLifecycle` provider (`nest/database/database-lifecycle.service.ts`): `buildApp()` opens it through `open()` (which binds the ORM to later swaps and runs the schema bootstrap below), the shutdown closes it through `close()`, and a restore or the demo reset swaps the file only through the database backup port, `DATABASE_BACKUP` (`nest/database/database-backup.interface.ts`; the SQLite implementation is `nest/backup/sqlite-database-backup.ts`: `VACUUM INTO` snapshot, close, atomic file swap, `reopen()`). The port works on `DatabaseLifecycle.file`, the one resolved path (`TREK_DB_FILE` or `data/travel.db`), and a snapshot that fails fails the backup rather than archiving the live file. `MaintenanceRepository` is provided only by `MaintenanceModule`'s factory and injected everywhere else; no consumer constructs it. A provider that has to follow every reopen (the demo reset job saves the first demo baseline after a restore's re-bootstrap seeded the example trips) registers with `DatabaseLifecycle.onReopened()`, which runs after the reopen's schema bootstrap; a listener contains its own failures, since one that throws fails the reopen. MikroORM's migrations (`db/migrations/`) are the only schema source, **including for tests**: the hand-kept `schema.ts`/`migrations.ts`/`seeds.ts` builders and the parity test that guarded them are gone. Seeding is the MikroORM seeders in `db/seeders/`, applied by `db/orm.ts` from `buildApp()` before anything reads. An install the retired positional runner migrated (a `schema_version` row, no `mikro_orm_migrations` rows) is baselined by `db/legacy-baseline.ts`: the migrations whose `Legacy migration step N` docstring is ≤ its version are recorded as executed (never replayed) in the same transaction as the migrator run, while the baseline migration itself still runs first, as the legacy runner's `createTables()` did on every boot. It refuses the boot when `schema_version` is not exactly one row holding an integer ≥ 1, or is above the last mapped step (258); a value from 1 to 258 is read as dev's steps of those numbers, so a pre-ORM feature-branch database whose steps differ is not detected (the Tours branch is the one case it cuts back). Recorded `mikro_orm_migrations` names this build does not ship refuse it too (`refuseNewerDatabase`), whether a newer release or a development build wrote them. 4.3.x and earlier have no such check and start on a database 5.x migrated. Before a boot applies pending migrations to a file database that holds anything, `db/pre-migrate-snapshot.ts` writes a `VACUUM INTO` copy next to it (`pre-migrate-<schema>-<time>.db`, `<schema>` being `legacy-<schema_version>` or the last recorded migration's timestamp; the newest `TREK_DB_PRE_MIGRATE_SNAPSHOT_KEEP` stay) and the newer-database refusal names the matching copy; a copy that cannot be written refuses the boot unless `TREK_DB_PRE_MIGRATE_SNAPSHOT=false`. It is off under `NODE_ENV=test` unless a suite sets that variable to true, and a restore's re-bootstrap skips it (the archive is the copy). After the migrator, `db/email-case-index.ts` creates the case-insensitive unique index on `users.email` that its migration had to defer on an install holding two accounts whose emails differ only in case (flag `email_case_index_pending`). `db/orm-driver.ts` binds the ORM to that same connection instead of opening a second one — with `:memory:` under test, a second connection is a second, empty database. Kysely statements (`this.kysely<...>()`) type against `DB` from `db/kysely/db.ts`, narrowed with `Pick<DB, 'trips' | 'days'>`; those files are generated from the migrated schema by `scripts/generate-db-types.ts`, so a migration that adds or changes a column is followed by `npm run gen:db-types`, never by a hand-written table interface. Every read and write goes through a repository in `db/repositories/` (each extends the shared `TrekRepository` base in `db/repositories/_shared/`, which validates the request context before delegating to MikroORM) and, for multi-statement writes, `UnitOfWork.transactional(...)` (`nest/database/unit-of-work.ts`, provided by the global `OrmModule`) — there is no `DatabaseService`/`DatabaseModule` to inject any more. Entrypoints outside an HTTP request — an MCP tool call, a plugin RPC dispatch, a WebSocket message, a cron job, boot-time seeding, a backup restore — open one explicitly with `withRequestContext()` (`nest/database/request-context.ts`), since only the pathless `mikroOrmRequestContext` middleware `buildApp()` mounts (with `@mikro-orm/nestjs`'s own `registerRequestContext` turned off in `app.module.ts`, UPLOADS-P16) forks an `EntityManager` per HTTP request. `NODE_ENV=test` ⇒ isolated `:memory:` DB per vitest worker, opened from a snapshot `tests/global-setup.ts` migrates once per run; `TREK_DB_FILE` ⇒ explicit file DB (Playwright harness).
 
 ## Rules for new code
 
diff --git a/server/src/db/pre-migrate-snapshot.ts b/server/src/db/pre-migrate-snapshot.ts
index f9a63226d..6ecab6f39 100644
--- a/server/src/db/pre-migrate-snapshot.ts
+++ b/server/src/db/pre-migrate-snapshot.ts
@@ -8,10 +8,12 @@ import path from 'node:path';
 /**
  * A copy of the database taken right before a boot migrates it.
  *
- * Migrations only go forward, and a database a newer TREK migrated is refused
- * by the older one (`refuseNewerDatabase`). Without a copy from before the
- * upgrade, going back to the previous image means restoring a backup, and
- * automatic backups are off by default. So the boot takes one itself: a
+ * Migrations only go forward. An image from 5.0 on refuses a database a newer
+ * TREK migrated (`refuseNewerDatabase`), but 4.3.x and earlier do not check:
+ * they start on the newer schema without a warning and run on what they
+ * understand of it. Either way, going back to the previous image means going
+ * back to a copy from before the upgrade, and automatic backups are off by
+ * default. So the boot takes one itself: a
  * `VACUUM INTO` snapshot next to the database file, named after the schema it
  * holds, e.g. `pre-migrate-legacy-244-20261008T091500Z.db` for a v4.3.3
  * install or `pre-migrate-20200101042300-….db` for one the migrator already