Add browser-only UI customization (density/layout/JSON/paging) + query-safe static asset routing

[swordfish444]

Summary (target: development)

Adds a browser-only UI Customization panel to the Android Debug Database web UI (layout/
text/paging), plus a small server fix so index.html?… (and other static assets) load
correctly when query parameters are present.

Why

When inspecting wide tables and/or large JSON blobs, the current UI often forces heavy
horizontal scrolling and doesn’t let you tune density/page size. This PR improves
readability and navigation without changing any database/server behavior.

What changed

• Adds a Customize UI button next to Run Query that opens an in-page customization
  view (?view=customize) with a “Back to Data” link (supports browser back/forward via
  history.pushState when available).
• New debug-db-base/src/main/assets/ui-customization.js (self-contained) + updates to
  debug-db-base/src/main/assets/index.html and debug-db-base/src/main/assets/custom.css
  to support:
  • Table width: fixed / full width / fluid (max width)
  • Row density: compact / normal / comfortable
  • Sticky table header while scrolling
  • Wrap long text + optional max column width
  • JSON display mode for valid JSON object/array cells: raw / wrapped / pretty-printed
  • Rows per page (10/25/50/100), wired into DataTables
• Persists settings in browser localStorage only (per-browser), with “Reset to defaults”;
  defaults match existing behavior.
• Updates debug-db-base/src/main/assets/app.js to:
  • Initialize customization (no-op if the script isn’t present)
  • Apply saved page length at DataTable creation
  • Notify customization module when a DataTable is created (for JSON formatting + redraw
    handling)
• Fixes debug-db-base/src/main/java/com/amitshekhar/server/RequestHandler.java to strip
  query params for static asset lookup + MIME detection (API routes still receive the full
  route with query params). This enables /?view=customize and generally makes index.html?…
  safe.

Demo

Note: the button icon doesn't load because index.html is opened as a file in the Loom video.

Loom video: https://www.loom.com/share/0f28072dac494055a4bae16470c88358

How to test

1. Run any app with debug-db enabled and open the Debug DB URL in a browser.
2. Click Customize UI → toggle settings → click Apply.
3. Refresh the page to confirm settings persist; use Reset to defaults to clear.
4. Verify existing behavior still works: DB/table list, Run Query, CRUD, Download DB.

[swordfish444]

@amitshekhariitbhu Can you please review? Simple changes that add HUGE value to this project. Would love to get this merged ASAP.

Thank you in advance 🙇