fix: send browser User-Agent from galaxynovels fetch wrappers (#2442)

[RibatTRW]

What

Galaxy Novels (galaxynovels, plugins/arabic/galaxynovels.ts, version
1.1.0) shows the novel listing, but opening any chapter fails with "Could not
reach site (403)". User report: 2026-08-19, LNReader 2.1.0, Android 13.
Bug label, severity Other.

Why: root cause

The plugin does all fetching through the shared fetchApi
(src/lib/fetch.ts). Its makeInit sends: Connection, Accept,
Accept-Language, Sec-Fetch-Mode, Accept-Encoding. It sends no User-Agent.
galaxynovels.com is fronted by Cloudflare with a bot-fight rule that returns
403 on every path except the /novels/ listing when the request has no
User-Agent (curl-like UAs are blocked too). Browser-like UAs return 200
(verified live 2026-08-25, exact makeInit header set).

Failure flow inside the plugin: parseChapter calls the chapter API first, it
403s, the catch swallows it, the HTML fallback 403s, fetchHtml throws "Could
not reach site (403)". That is the exact user-facing error.

Design ruling (spec-2442 D1): fix per-plugin, not in the shared lib. Adding
the UA in makeInit would change behavior for every source, out of this
issue's blast radius.

How

• plugins/arabic/galaxynovels.ts: add private static readonly BROWSER_UA
  (exact Android Chrome UA verified in the probe matrix) and pass
  { headers: { 'User-Agent': GalaxyNovels.BROWSER_UA } } in both fetch
  wrappers. Every call site flows through one of the two wrappers (D2).
• Version 1.1.0 -> 1.2.0 (D5) so cached installs refetch.
• HTML fallback intentionally untouched (D4): chapter HTML pages are
  Cloudflare-blocked even with a browser UA (verified); the API path is the
  only viable read path today.

Tests

Deterministic, no network: tests/regression-2442.mjs +
tests/fixtures/2442/ (captured 2026-08-25). The global fetch stub emulates
the Cloudflare rule: no User-Agent header -> HTTP 403; otherwise it serves
the matching fixture by URL. REQ-1 (every fetch init recorded during the run
carries a User-Agent) is the regression pin.

node tests/regression-2442.mjs

Check	Before (e1dcd06)	After
REQ-1 every fetch init carries a User-Agent header	FAIL (5 of 5 UA-less)	PASS
N-1..N-6 parseNovel (name, cover, author, status, genres, 5 chapters)	FAIL (403)	PASS
C-1 parseChapter content (>= 200, starts with الفصل 1)	FAIL (403)	PASS
C-2 403 rejects with /Could not reach site (403)/	PASS	PASS
C-3 chapter API was fetched (no silent fallback)	PASS	PASS

Baseline: 8 FAILING (RED, bug reproduced at e1dcd06) -> after fix: 10/10
ALL GREEN.

Live check (node scripts/live-check-plugin.js "plugins/arabic/galaxynovels.ts", 2026-08-25): popularNovels PASS (20),
searchNovels PASS (1), parseNovel PASS (488 chapters), parseChapter PASS
(3743 chars).

Gates

• npx prettier --check plugins/arabic/galaxynovels.ts tests/regression-2442.mjs: clean. Note: 5 pre-existing prettier drift spots in galaxynovels.ts were normalized (pure formatting, no semantic change; the suite stays 10/10) so the mandatory prettier gate can pass.
• npx eslint plugins/arabic/galaxynovels.ts: clean.
• npx tsc --noEmit: 23 pre-existing errors, all in untouched plugins (mvlempyr, mynovels, novelight, and others); zero in galaxynovels.ts and zero in tests/.
• No lockfile churn. No generated files. Shared lib untouched.

Note for reviewer

• One U+2014 exists inside tests/fixtures/2442/chapter-api.json: it is
  captured site content (Arabic novel prose inside content_html), kept
  verbatim per the fixture contract. All authored text (code diff, commit
  messages, this description) has zero em dashes.
• eslint.config.js has no .mjs globals at base e1dcd06. That gap is being
  fixed by the open [riwyat] Empty chapter: — الفصل 871 : هي تظهر! #2465 PR (commit 631dca9). This PR does not touch the
  eslint config to avoid a merge conflict with fix: restore Riwyat covers and chapter content (#2465) #2466.

Closes #2442

---

Automated contribution via the LNReader Dev Ops pipeline (builder-bob, Hermes Agent).

[RibatTRW]

Hygiene follow-up from review card t_fcfaa066 pushed as 74b11d7 on issue-2442:

• F-STD-1 — the regression-bundle.cjs temp-bundle write/require/unlink sequence in tests/regression-2442.mjs is now wrapped in try/finally, so a crashed/killed run can no longer leave the artifact behind (git check-ignore regression-bundle.cjs = NOT ignored: .gitignore's .js entry is a literal basename and this is .cjs). Verified empirically by injecting a throw at the require site in a scratch copy of the suite: process exits non-zero AND the temp file is removed; a normal run leaves git status --porcelain clean.
• F-STD-2 — \d → \\d in the N-6 FAIL banner template literal (line 135). eslint no-useless-escape at 135:55 cleared; the remaining 12 errors are the known base-config no-undef gap for .mjs, fixed by fix: restore Riwyat covers and chapter content (#2465) #2466 commit 631dca9 as documented.

Gates re-run locally: node tests/regression-2442.mjs → ALL GREEN 10/10, exit 0; prettier clean; eslint shows only the 12 documented no-undef errors.

Consistency note: tests/regression-2465.mjs (#2466) has the identical unguarded temp-file pattern — left untouched here per fix-card scope; flagging for whoever next touches that file.