Feat: Add bulk actions for case analysis and deletion

Introduces a new `/web/cases/bulk` endpoint to handle multiple case
actions simultaneously.

This change adds the following:
- A new `bulk` module for handling bulk operations.
- The `handle_bulk_action` function in `bulk.rs` to dispatch to specific
  actions.
- `bulk_analyze` and `bulk_delete` functions to process the actions.
- Updates `Cargo.toml` and `Cargo.lock` to include necessary
  dependencies: `form_urlencoded`, `serde_core`, `serde_html_form`, and
  `serde_path_to_error`.
- Modified `axum-extra` features to include `form`.
- Adds checks for deleted cases in `collect_pending` for both analysis
  and transcription recovery.
- Renames and modifies `handle_close_case` to `handle_analyze_case` in
  `case_actions.rs` to better reflect its functionality.
- Adds a new `handle_delete_case` and `handle_undo_delete` to
  `case_actions.rs`.
- Updates `my_cases.html` and `case_detail.html` to support bulk
  actions, including checkboxes, a bulk action bar, and an "Undo last
  delete" feature.
- Modifies `handle_audio` and `scan_cases` in `web.rs` to respect delete
  markers.
- Updates `analyze_test.rs` with new request builders for analyze and
  delete actions.

server/templates/case_detail.html

@@ -45,16 +45,15 @@ header form { margin: 0; }
 <div class="actions">
 {% if has_document %}
 <a class="doc-link" href="/web/cases/{{ case_id }}/document">Ergebnis öffnen</a>
-{% if can_reanalyze %}
-<form method="post" action="/web/cases/{{ case_id }}/reanalyze"><button type="submit">Neu analysieren</button></form>
 {% endif %}
-{% else if analyzing %}
+{% if analyzing %}
 <span class="analyzing">wird analysiert …</span>
-{% else if can_close %}
-<form method="post" action="/web/cases/{{ case_id }}/close"><button type="submit">Fall abschließen</button></form>
+{% else if can_analyze %}
+<form method="post" action="/web/cases/{{ case_id }}/analyze"><button type="submit">{% if has_document %}Neu analysieren{% else %}Analysieren{% endif %}</button></form>
 {% else if llm_missing %}
 <span class="llm-missing">LLM-Analyse nicht konfiguriert</span>
 {% endif %}
+<form method="post" action="/web/cases/{{ case_id }}/delete" style="margin-left:auto;display:inline"><button type="submit">Entfernen</button></form>
 </div>
 
 <h2>Aufnahmen ({{ recordings.len() }})</h2>