feat(ui): seven quick actions on the homepage — operations visible before upload - #145

…fore upload

Before a file was chosen, the homepage's tool card offered no concrete
operation — just the Convert/Compress toggle and an empty target-format
dropdown — and the PDF tools sat as small text links in a "More tools" box
below the fold. First visible step of surfacing operations earlier:

- The tool card now shows, under the drop zone, an "Or choose directly" label
  with seven chip links — Compress PDF, JPG to PDF, Word to PDF, Split PDF,
  Extract PDF pages, HEIC to JPG, Compress image (KB/MB) — and "All tools →".
  Every chip targets a page that already exists; "(KB/MB)" says file size,
  since pixel resizing isn't built.
- Homepage-only: partials/convert_tool.html also renders /compress and the 12
  /convert/<pair> pages, so a show_quick_actions flag set only by index()
  keeps self-links and a diluted row off them.
- Server-rendered <nav> + list of <a>, no inline JS (CSP), links always in
  the initial HTML (IA invariant G6). The chips are an idle-state shortcut:
  app.js setQuickActionsVisible() hides them once files are chosen and shows
  them again when the selection is cleared — otherwise they pushed the
  Convert button ~345 px down on a phone (found in review).
- Secondary chip styling so Convert stays the card's only brand-filled
  control; 44 px touch targets; label text-gray-400 (6.9:1) and
  brand-light link (5.9:1) for AA contrast; focus ring on every link.
- The "More tools" box is removed (its links live in the chips); the subline
  gains "PDF". Redact is no longer teased on the homepage — footer and /tools
  still link it when enabled, and it never belongs among idle chips (free
  path before paid).
- scripts/i18n.py update passes --ignore-obsolete, so removed msgids are
  dropped instead of piling up as "#~" blocks (none since c8fc734).

Deferred on purpose: category links (PDF · Images · …) until /tools has
matching sections; the toggle, dropdown and Convert button until the
Smart-Drop step replaces them.

Tests: test_homepage_quick_actions.py replaces test_homepage_more_tools.py —
exact link list on /en and /de, localized labels without leakage, absent on
/compress and a pair page, every target answers 200, <main> never links
/redact, app.js hides/shows the row; the heading-outline guards moved to
test_homepage_outline.py (h2 pins 4/5/4). Rebased onto #143 (catalogs
regenerated, 0 fuzzy, 0 obsolete). Browser-checked at 1280 px and 375 px,
including the file-selected state.

Full suite 1230 green (63 skipped); ruff + format + template-class gate +
i18n-drift clean; Tailwind bundle tailwind.86732528.css reproducible.
Reviewed by security-auditor (pass) and code-reviewer (nits applied).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>