feat(projects): list + create API and creatable ProjectAutocomplete (T4)

- GET /api/projects returns the shared global list; POST /api/projects
  creates a project, deduped case-insensitively (F3).
- Repository find-or-create trims and matches on lower(name); a unique index
  on lower(name) enforces the same rule at the DB (replacing the case-
  sensitive column unique constraint) — migration 0001.
- ProjectAutocomplete: creatable autocomplete that lists projects, offers to
  create an unknown name inline, and selects it without reload.
- Integration test (dedupe/list against Postgres) + component test.

server/db/migrations/meta/_journal.json

@@ -8,6 +8,13 @@
       "when": 1779913917235,
       "tag": "0000_loving_black_bird",
       "breakpoints": true
+    },
+    {
+      "idx": 1,
+      "version": "7",
+      "when": 1779916898127,
+      "tag": "0001_boring_randall",
+      "breakpoints": true
     }
   ]
 }