warp_engine 0.5.1: the device_grants migration collided with the host's

`db:migrate` on the catalog API stopped before running anything:

    Multiple migrations have the version number 20260819000001.

The engine appends its `db/migrate` to the host's migration paths instead of
copying migrations in, so engine and host share one version namespace. Both had
picked 20260819000001 on the same day by the same habit — the engine for
device_grants, apps/api for carry_the_store_config_in_the_registry — and neither
repository could see the other's number.

Worse than a clash of our own making: it takes the *host's* migrations down with
it, for the whole application, before anything runs.

device_grants is renumbered to 20260819093412 — a real second-resolution
timestamp, which is the actual defence. A round hand-written number is precisely
what another repository lands on. Nothing had run it in production, so this is a
rename rather than a data migration; a host that already applied the old version
renumbers its schema_migrations row.

The older engine migrations keep their round numbers: renumbering one that has
been deployed everywhere is worse than the risk it carries. They are named in the
new spec's grandfather list rather than excused by a rule that would also let the
next one through.

That spec found a second thing, older than this change: the install template
creates `application_tokens`, and so does one of our own migrations — so a fresh
host runs CREATE TABLE twice and has to delete the block from its generated copy
by hand, which is exactly what teletype-orbit's migration header describes. I had
just made it worse by putting device_grants in the template too; that is out
again, and the template says why. `application_tokens` is grandfathered and left
for a change that is not a hotfix.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

lib/generators/warp_engine/install/templates/create_warp_engine_tables.rb

@@ -98,27 +98,11 @@ class CreateWarpEngineTables < ActiveRecord::Migration[8.0]
       t.index :deleted_at
     end
 
-    # Device sign-in for clients that have no browser of their own (RFC 8628).
-    # Short-lived rows: one exists for the minute or two between "the client asked"
-    # and "the person answered". Only used where access_token_owner_class is set.
-    create_table :device_grants do |t|
-      t.string :device_code, limit: 64, null: false
-      t.string :user_code, limit: 16, null: false
-      t.string :client_name, limit: 128
-      t.string :subject_type, limit: 128
-      t.bigint :subject_id
-      t.bigint :application_token_id
-      # The issued token in the clear, cleared on the poll that hands it over — see
-      # the model. Everything else about a token is stored as a digest.
-      t.string :issued_token, limit: 64
-      t.datetime :approved_at, precision: 3
-      t.datetime :denied_at, precision: 3
-      t.datetime :expires_at, precision: 3, null: false
-      t.timestamps precision: 3, null: true
-      t.index :device_code, unique: true
-      t.index :user_code, unique: true
-      t.index :expires_at
-    end
+    # NOTE: device_grants is NOT created here. It ships as its own migration in the
+    # engine's db/migrate, which the host runs from the appended path — so creating it
+    # here as well would be a second CREATE TABLE for the same name. The same is true
+    # of application_tokens below, which predates this note and is why a host
+    # installing today has to delete that block from its copy by hand.
 
     create_table :downloads do |t|
       t.string :file_path, null: false

lib/warp_engine/engine.rb

@@ -10,6 +10,15 @@ module WarpEngine
 
     # A jövőbeli katalógus-migrációk az engine db/migrate-jéből futnak a host
     # rails db:migrate-jével, másolás nélkül.
+    #
+    # FONTOS: emiatt az engine és a host migrációi EGY névtérben vannak, és két
+    # azonos verziószám a host `db:migrate`-jét indulás előtt megállítja
+    # (DuplicateMigrationVersionError) — nem a miénket, hanem az övét, az egész
+    # alkalmazásban. Az engine migrációi ezért **valódi, másodperc-pontosságú
+    # időbélyeget** kapnak (20260819093412), soha nem kerek kézzel írt számot
+    # (20260819000001): pont az utóbbiakra ír rá egy host, ami ugyanaznap ugyanezzel
+    # a szokással ír migrációt. Így ütközött a device_grants a katalógus-API
+    # `carry_the_store_config_in_the_registry`-jével.
     initializer "warp_engine.append_migrations" do |app|
       unless app.root.to_s.start_with?(root.to_s)
         config.paths["db/migrate"].expanded.each do |path|

lib/warp_engine/version.rb

@@ -1,5 +1,5 @@
 module WarpEngine
-  VERSION = "0.5.0"
+  VERSION = "0.5.1"
 
   # The header every API response carries. Named here rather than written out at the one
   # place that sets it: clients read it, the README documents it, and a string in three