react-bootstrap migration, review & parser fixes

UI / react-bootstrap:
Migrate client components to react-bootstrap (Card, Table, Form,
Alert, Badge, Nav, Button, Spinner, Row, Col): the ZXDB explorers
and detail pages (Labels, Genres, Languages, MachineTypes, Releases,
Entries), TapeIdentifier, home page, Navbar and ThemeDropdown.
Server components (home, zxdb hub, magazines, issues) keep raw
HTML+className — react-bootstrap barrel imports resolve to undefined
under Turbopack in server components. Replace bi bi-* CSS icons with
react-bootstrap-icons. Add aria-labels to search inputs and
visually-hidden captions to data tables.

Code-review remediation (docs/todo.md):
- FileViewer: replace useState-as-effect with a proper useEffect.
- register.service: restore request-level caching of parsed registers.
- middleware: convert .js to .ts, dev-only request logging.
- Extract shared types to src/types/zxdb.ts; add src/server/repo
  barrel for incremental per-domain splitting.
- Extract helpers: parseIdList (params.ts), serialize (serialize.ts),
  buildRegisterSummary/isInfoLine (register_helpers.ts).
- Add loading.tsx skeletons for dynamic ZXDB detail routes.
- generateMetadata + notFound() on entry/release/label detail pages.
- opengraph-image: stable keys; ThemeDropdown: drop hardcoded cookie
  domain; remove unused page.module.css.

Register parser & data:
- Update data/nextreg.txt from upstream tbblue (SpectrumNext FPGA):
  0x04/0x0A/0x0F/0x80/0x81 bit changes, new Issue 5 board id, 0x43
  renamed "Palette Control", 0xF0/0xF8/0xF9/0xFA now "Issues 4 and 5
  Only".
- Add reg_44 custom parser for 0x44 (Palette Value 9-bit): the two
  consecutive writes render as separate "1st write" / "2nd write"
  modes.
- Skip commented-out register headers so the disabled 0xA3 block no
  longer leaks a phantom register.
- Add detailHasContent guard so body-less registers (0xC7/0xCB/0xCF/
  0xFF) and 0xF0's leading blank no longer emit empty tab strips.
- Capture 0xF0's leading "Issues 4 and 5 Only" line as register text.
- Add isIssueRestricted (case-sensitive) to detect the issue badge
  across rewording without flagging per-bit "(issue 5 only)" notes;
  update badge label to "Issues 4 & 5 Only".

claude-opus-4-8@lucy

src/app/zxdb/magazines/[id]/page.tsx

@@ -1,6 +1,7 @@
 import Link from "next/link";
 import { notFound } from "next/navigation";
-import { getMagazine } from "@/server/repo/zxdb";
+import { getMagazine } from "@/server/repo";
+import { Link45deg, Archive } from "react-bootstrap-icons";
 import ZxdbBreadcrumbs from "@/app/zxdb/components/ZxdbBreadcrumbs";
 
 export const metadata = { title: "ZXDB Magazine" };
@@ -28,7 +29,7 @@ export default async function Page({ params }: { params: Promise<{ id: string }>
       <div className="text-secondary mb-3">Language: {mag.languageId}</div>
 
       <div className="mb-3 d-flex gap-2 flex-wrap">
-        <Link className="btn btn-outline-secondary btn-sm" href="/zxdb/magazines">← Back to list</Link>
+        <Link className="btn btn-outline-secondary btn-sm" href="/zxdb/magazines">&larr; Back to list</Link>
         {mag.linkSite && (
           <a className="btn btn-outline-secondary btn-sm" href={mag.linkSite} target="_blank" rel="noreferrer">
             Official site
@@ -42,6 +43,7 @@ export default async function Page({ params }: { params: Promise<{ id: string }>
       ) : (
         <div className="table-responsive">
           <table className="table table-sm align-middle">
+            <caption className="visually-hidden">Magazine issues</caption>
             <thead>
               <tr>
                 <th style={{ width: 200 }}>Issue</th>
@@ -71,13 +73,13 @@ export default async function Page({ params }: { params: Promise<{ id: string }>
                     <div className="d-flex gap-2">
                       {i.linkMask && (
                         <a className="btn btn-outline-secondary btn-sm" href={i.linkMask} target="_blank" rel="noreferrer" title="Link">
-                          <span className="bi bi-link-45deg" aria-hidden />
+                          <Link45deg aria-hidden />
                           <span className="visually-hidden">Link</span>
                         </a>
                       )}
                       {i.archiveMask && (
                         <a className="btn btn-outline-secondary btn-sm" href={i.archiveMask} target="_blank" rel="noreferrer" title="Archive">
-                          <span className="bi bi-archive" aria-hidden />
+                          <Archive aria-hidden />
                           <span className="visually-hidden">Archive</span>
                         </a>
                       )}