feat: full feature buildout — streaming, i18n, mastery map, admin, jobs

Progressive lesson streaming via onSegment callback (fixes SSE for non-English
users — locale was shadowed in lesson-reader useEffect). Adds: BullMQ workers,
Redis stream buffer, token budget enforcement, Langfuse tracing, golden-eval
runner, Playwright e2e scaffolding, lesson depth/locale/preferences schema,
mastery map UI, admin panel (blueprints/users/reports/quality/misconceptions),
image queries, source citations, view transitions, reading animations, i18n
(next-intl), PDF export, surprise endpoint, and 402 passing unit tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

drizzle/migrations/meta/_journal.json

@@ -43,6 +43,90 @@
       "when": 1782070177922,
       "tag": "0005_site_email",
       "breakpoints": true
+    },
+    {
+      "idx": 6,
+      "version": "7",
+      "when": 1782074310619,
+      "tag": "0006_slim_ultragirl",
+      "breakpoints": true
+    },
+    {
+      "idx": 7,
+      "version": "7",
+      "when": 1750550400000,
+      "tag": "0007_lesson_locale",
+      "breakpoints": true
+    },
+    {
+      "idx": 8,
+      "version": "7",
+      "when": 1782133019007,
+      "tag": "0008_noisy_cloak",
+      "breakpoints": true
+    },
+    {
+      "idx": 9,
+      "version": "7",
+      "when": 1782133583085,
+      "tag": "0009_unique_wallflower",
+      "breakpoints": true
+    },
+    {
+      "idx": 10,
+      "version": "7",
+      "when": 1782200000000,
+      "tag": "0010_lesson_depth",
+      "breakpoints": true
+    },
+    {
+      "idx": 11,
+      "version": "7",
+      "when": 1782138081002,
+      "tag": "0011_smooth_thanos",
+      "breakpoints": true
+    },
+    {
+      "idx": 12,
+      "version": "7",
+      "when": 1782500000000,
+      "tag": "0012_user_preferences",
+      "breakpoints": true
+    },
+    {
+      "idx": 13,
+      "version": "7",
+      "when": 1782310455008,
+      "tag": "0013_illegal_random",
+      "breakpoints": true
+    },
+    {
+      "idx": 14,
+      "version": "7",
+      "when": 1782312574334,
+      "tag": "0014_faulty_namor",
+      "breakpoints": true
+    },
+    {
+      "idx": 15,
+      "version": "7",
+      "when": 1782313119046,
+      "tag": "0015_mighty_prowler",
+      "breakpoints": true
+    },
+    {
+      "idx": 16,
+      "version": "7",
+      "when": 1782400000000,
+      "tag": "0016_theme_map",
+      "breakpoints": true
+    },
+    {
+      "idx": 17,
+      "version": "7",
+      "when": 1782337567021,
+      "tag": "0017_married_betty_brant",
+      "breakpoints": true
     }
   ]
 }