ui: aggregated read on top, hide stale rows, wire /log tone toggle; prompts v8

- dashboard grid: explicit "header" area as the first row so the
    aggregated read panel renders at the top instead of being
    auto-placed after the named areas.
  - indicators: hide rows flagged stale (older than the group's
    freshness threshold). Server still computes stale_symbols;
    rendering can be re-enabled by removing the
    `{% if not is_stale %}` wrapper in indicators.html.
  - /log: add tone-changed to #log-content's hx-trigger and include
    it in cassandraSetTone's selector list — toggling Novice /
    Intermediate on the Log page was previously a no-op.
  - prompts: bump PROMPT_VERSION 7→8. Strengthen the rational-vs-
    irrational framing in the strategic-log system prompt from
    aspirational to mandatory ("a paragraph without both lenses must
    be rewritten"). Require the same lens in the per-group summary,
    cross-asset aggregate, and portfolio commentary overrides.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/templates/log.html

@@ -25,7 +25,7 @@
     <article id="log-content"
              class="log-page__content"
              hx-get="/api/log/by-date/{{ selected_iso }}?as=html"
-             hx-trigger="load"
+             hx-trigger="load, tone-changed"
              hx-swap="innerHTML">
       <div class="empty">loading log…</div>
     </article>