Drop the keyboard shortcuts; add a Re-read all button

The page carried the TUI's keymap -- screens on 1-8, / u a i r, the
report's arrows and s, the rule builder's ctrl+s and esc. Every one of
them already had a link, button or click, so they are gone, along with
the key numbers in the nav and the key hints in placeholders and
tooltips. The upload box still answers Enter and Space, which is what
makes it a button rather than a shortcut.

The forced import was reachable only by shift-clicking Import. It is now
a Re-read all button: every statement parsed again, including the ones
an import skips as unchanged -- what to run after a parser fix. Both
buttons disable while either runs.

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

internal/web/static/index.html

@@ -12,6 +12,7 @@
   <nav id="nav" aria-label="Screens"></nav>
   <div class="actions">
     <button type="button" id="retag" title="Re-apply rules.toml: retag everything and re-pair transfers">Retag</button>
+    <button type="button" id="reread" title="Re-read every statement, including ones unchanged since they were imported">Re-read all</button>
     <button type="button" id="import" class="primary" title="Import new statements from every account folder">Import</button>
   </div>
 </header>