fix(WP-0014): pre-flight compilation fixes, Tailwind pipeline, and admin seed

A2 — Compilation fixes:
- Remove inline FK constraints from Schema.sql; IHP schema compiler cannot
  parse them. Add 1744329600-restore-fk-constraints.sql migration to restore
  referential integrity at the DB level.
- Rename `#label` → `#label_` throughout to avoid clash with Haskell built-in.
- Fix `hub.id == hid` UUID comparisons to use `toUUID hub.id`.
- Replace non-existent `setStatus`/`respondJson` calls with
  `renderJsonWithStatusCode` throughout Api controllers.
- Fix qualified package import for `cryptohash-sha256` in Auth.hs.
- Add `CanSelect (Text, Text)` instance in Helper.View.
- Refactor HSX inline lambdas to named helper functions in 100+ views
  (GHC cannot infer types for anonymous functions inside quasi-quoted HSX).
- Fix missing imports (IHP.QueryBuilder, IHP.Fetch, Web.Routes, Only, etc.)
  across helpers and controllers.
- Remove duplicate `diffUTCTime` definition in BottleneckDetector.
- Change `createEventForHub` return type from `IO ResponseReceived` to `IO ()`.
- Seed type-registry vocabulary via 1744502400-seed-type-registries.sql
  (moved from Schema.sql where IHP does not execute INSERT statements).

A3 — Tailwind build pipeline:
- Add `tailwindcss` to flake.nix native packages.
- Uncomment `tailwind.exec` process in devenv shell config.
- Add tailwind/tailwind.config.js (scans Web/View/**/*.hs).
- Add tailwind/app.css with @tailwind directives.

A4 — Admin user seed:
- Add 1744416000-seed-admin-user.sql: inserts admin@inter-hub.local
  with bcrypt-hashed password admin1234! (cost 10).
- Add .env.example documenting all required environment variables
  and default admin credentials.

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

Web/View/AnnotationThreads/Show.hs

@@ -4,6 +4,7 @@ import Web.Types
 import Generated.Types
 import IHP.Prelude
 import IHP.ViewPrelude
+import Web.Routes ()
 
 data ShowView = ShowView
     { widget      :: !Widget
@@ -14,9 +15,9 @@ data ShowView = ShowView
 instance View ShowView where
     html ShowView { .. } = [hsx|
         <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
-            <a href={ShowWidgetAction { widgetId = widget.id }} class="hover:text-gray-700">{widget.name}</a>
+            <a href={ShowWidgetAction (widget.id)} class="hover:text-gray-700">{widget.name}</a>
             <span>/</span>
-            <a href={WidgetAnnotationThreadsAction { widgetId = widget.id }} class="hover:text-gray-700">Threads</a>
+            <a href={WidgetAnnotationThreadsAction (widget.id)} class="hover:text-gray-700">Threads</a>
             <span>/</span>
             <span>{thread.title}</span>
         </div>
@@ -24,7 +25,7 @@ instance View ShowView where
         <div class="max-w-2xl">
             <div class="mb-6">
                 <h1 class="text-2xl font-semibold">{thread.title}</h1>
-                {maybe mempty (\d -> [hsx|<p class="text-sm text-gray-500 mt-1">{d}</p>|]) thread.description}
+                {maybe mempty renderThreadDesc thread.description}
             </div>
 
             <div class="mb-4 flex items-center gap-3">
@@ -59,11 +60,17 @@ renderSeverityBar annotations =
         nonZero  = filter (\(_, n) -> n > 0) counts
     in if total == 0
         then mempty
-        else [hsx|
-            <div class="flex items-center gap-1">
-                {forEach nonZero (\(s, n) -> renderBarSegment s n total)}
-            </div>
-        |]
+        else renderSeverityBarItems nonZero total
+
+renderSeverityBarItems :: [(Text, Int)] -> Int -> Html
+renderSeverityBarItems nonZero total = [hsx|
+    <div class="flex items-center gap-1">
+        {forEach nonZero (renderBarSegmentPair total)}
+    </div>
+|]
+
+renderBarSegmentPair :: Int -> (Text, Int) -> Html
+renderBarSegmentPair total (s, n) = renderBarSegment s n total
 
 renderBarSegment :: Text -> Int -> Int -> Html
 renderBarSegment sev n total =
@@ -73,6 +80,9 @@ renderBarSegment sev n total =
     </div>
 |]
 
+renderThreadDesc :: Text -> Html
+renderThreadDesc d = [hsx|<p class="text-sm text-gray-500 mt-1">{d}</p>|]
+
 barColor :: Text -> Text
 barColor "low"      = "bg-gray-300"
 barColor "medium"   = "bg-blue-400"