feat(tariff-lab): DB-backed draft tariffs + named published versions

Experimenting used to mean publishing — churning the immutable version
history and risking real tickets pricing against a half-baked card while
the admin iterated. The lab is now a true sandbox:

- tariff_drafts table (migration 0021): MUTABLE by design — the one
  exception to "editing publishes a version"; a draft prices nothing and
  signs nothing. Drafts are validated + tz-stamped on save exactly like a
  publish, so a saved draft always simulates and never fails at publish.
- CRUD under /api/tariff/drafts (list tariff:read, mutations
  tariff:update); publishing a draft goes through the normal immutable
  POST /api/tariff/versions path.
- Lab UI rebuilt: sidebar lists lab drafts AND the full published history
  (click any to price against it); main pane cut to pure entry/exit
  (ticket loader, payment, category inputs dropped); the composer form is
  extracted to TariffEditorForm.tsx and reused in a modal (new drafts
  prefill from the active card); per-draft Publish with confirm.
- tariff_versions.name (migration 0022): optional label stamped at
  publish — carried from the lab draft, or typed in the composer's new
  optional field — so history reads "Winter 2027", not UUID prefixes.
- Includes the composer UI + sq/en labels for the package mode (engine
  landed in d9e6c13) and the "Flat price / hour" relabel.

5 new server integration tests (RBAC, roundtrip, validation, tz-stamp +
simulate + publish w/ name); server suite 288 green.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

packages/db/drizzle/0021_tariff_drafts.sql

@@ -0,0 +1,14 @@
+-- Tariff-lab drafts (2026-07-05). A mutable scratchpad for the lab: the admin composes
+-- experimental rate cards here, simulates them against hypothetical stays, and only
+-- PUBLISHES (normal immutable tariff_versions path) when satisfied. Deliberately mutable —
+-- a draft prices nothing and signs nothing; experimenting through real publishes would
+-- churn permanent versions and risk a wrong card going live. See wiki/concepts/tariff.md.
+CREATE TABLE `tariff_drafts` (
+	`id` text PRIMARY KEY NOT NULL,
+	`name` text NOT NULL,
+	`currency` text NOT NULL,
+	`structure` text NOT NULL,
+	`created_by` text,
+	`created_at` text DEFAULT (current_timestamp) NOT NULL,
+	`updated_at` text DEFAULT (current_timestamp) NOT NULL
+);

packages/db/drizzle/0022_tariff_version_name.sql

@@ -0,0 +1,6 @@
+-- Optional name on published tariff versions (2026-07-05). The lab's draft workflow gave
+-- rate cards human names; published versions were only tellable apart by effective date +
+-- UUID prefix. The name is stamped at publish (carried from the lab draft, or typed in the
+-- composer) and is immutable like the rest of the row. Nullable — old versions and unnamed
+-- publishes are fine.
+ALTER TABLE `tariff_versions` ADD `name` text;

packages/db/drizzle/meta/_journal.json

@@ -148,6 +148,20 @@
       "when": 1781886300000,
       "tag": "0020_entry_presence_bypass",
       "breakpoints": true
+    },
+    {
+      "idx": 21,
+      "version": "6",
+      "when": 1781886400000,
+      "tag": "0021_tariff_drafts",
+      "breakpoints": true
+    },
+    {
+      "idx": 22,
+      "version": "6",
+      "when": 1781886500000,
+      "tag": "0022_tariff_version_name",
+      "breakpoints": true
     }
   ]
 }