docs: collapse FAQ + Troubleshooting into <details> accordions

Same shape as the MCP-tools accordion shipped earlier — both pages
are scanned (find your question / find your symptom) rather than
read top-to-bottom, so a flat list of 16 + 11 entries was hostile
to the way users actually arrive at the page.

Changes:

1. Renamed `docs-mcp-category` → `docs-accordion` in CSS + JSX.
   The class is now used by 3 docs pages (MCP, FAQ, Troubleshooting),
   so the MCP-specific name was misleading.  Bulk-replaced 17 hits
   in Mcp.jsx; only one CSS block in landing.css; comment block on
   the CSS rule updated to enumerate the three callsites.

2. Faq.jsx — every h3-question + answer block wrapped in
   `<details className="docs-accordion">` / `<summary>`.  All
   collapsed by default.  Header-line subtitle adds a hint about
   Ctrl+F auto-opening matches.

3. Troubleshooting.jsx — same conversion.  All 11 symptoms
   collapsed.  One symptom heading rewritten: "Dashboard logs" was
   a non-symptom (described where to find logs for bug reports);
   renamed to "Where to grab logs for a bug report" so the summary
   line actually tells the reader what's behind it.

4. Generic body-padding rule added to the accordion CSS:
   `.docs-accordion[open] > *:not(summary) { padding-left/right: 1rem }`
   so any direct child (whether docs-mcp-tools, intro <p>, or a
   bare <ul>/<ol>) gets consistent inset.  Avoids needing per-page
   padding rules.

Native <details> behaviours preserved:
- Keyboard accessible (Enter/Space toggles)
- Find-in-page auto-opens matched accordion
- Hash-fragment links auto-open parent <details>
- Zero JS

The 27 entries that previously took ~10 viewport-heights to scroll
past now collapse to roughly one page-height of summaries.

Author: Sbussiso