Fix Save & Re-voice silently discarding every speaker edit

Reported: editing a speaker, then "Save & Re-voice", did nothing.

This is a regression from e810b49 (the voice-queue commit), which deleted
the body of queueVoiceRegenOnSave but left the edit form calling it as
onsubmit="return queueVoiceRegenOnSave(...)". A JS handler that falls off
the end returns undefined, which is falsy, so the browser cancelled the
submit. The PUT never fired: no request, no error, no change. It affected
every field on the speaker edit form - name, gender, traits, accent - not
just re-voicing.

- Re-voicing is now hooked to hx-on::after-request, so the new profile is
  on disk before the voice is rebuilt from it, and a failed save does not
  queue work. The handler re-reads the name from the swapped row, so a
  rename regenerates under the new name instead of the old one.
- The backend was never at fault: a full round-trip through
  PUT /api/speakers/0 with the record's own values leaves every field
  byte-identical.
- New tests/test_speaker_edit_submit.py guards the class of bug, not just
  this instance: no onsubmit="return ..." in the row template, and any
  onsubmit that returns a value anywhere must return a literal true/false.
  Comments are stripped before scanning, since the hazard is documented in
  one. Verified by reintroducing the bug - 3 of the 4 tests fail.

Suite: 688 passed, 8 pre-existing.

tests/test_speaker_edit_submit.py

@@ -0,0 +1,95 @@
+"""Guards on the speaker edit form's submit behaviour.
+
+Regression: the voice-queue work emptied ``queueVoiceRegenOnSave`` but left
+``onsubmit="return queueVoiceRegenOnSave(...)"`` in the edit form. A handler
+that falls off the end returns ``undefined``, which is falsy, so the browser
+cancelled the submit and every speaker edit was silently discarded - the save
+never reached the server, so nothing looked broken and nothing errored.
+
+An ``onsubmit`` that returns a value must return a boolean deliberately.
+"""
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+TEMPLATES = Path(__file__).resolve().parents[1] / "umbraaudio" / "web" / "templates"
+
+# onsubmit="return someFn(...)" - the cancelling shape
+ONSUBMIT_RETURN = re.compile(r'onsubmit="return\s+([A-Za-z_$][\w$]*)\s*\(')
+FUNC_DEF = re.compile(
+    r"function\s+([A-Za-z_$][\w$]*)\s*\([^)]*\)\s*\{", re.MULTILINE
+)
+# Comments quote these patterns when documenting the hazard, so strip them
+# first or the scanner reports the documentation as if it were live markup.
+COMMENTS = re.compile(r"\{#.*?#\}|<!--.*?-->", re.DOTALL)
+
+
+def _strip_comments(text: str) -> str:
+    return COMMENTS.sub("", text)
+
+
+def _all_template_text() -> str:
+    return _strip_comments(
+        "\n".join(p.read_text() for p in TEMPLATES.rglob("*.html"))
+    )
+
+
+def _function_bodies(text: str) -> dict[str, str]:
+    """Map function name -> body text, brace-matched."""
+    bodies: dict[str, str] = {}
+    for m in FUNC_DEF.finditer(text):
+        start = m.end()
+        depth = 1
+        i = start
+        while i < len(text) and depth:
+            if text[i] == "{":
+                depth += 1
+            elif text[i] == "}":
+                depth -= 1
+            i += 1
+        bodies[m.group(1)] = text[start : i - 1]
+    return bodies
+
+
+def test_no_onsubmit_handler_can_cancel_the_speaker_edit() -> None:
+    """The edit form must never gate its own submission on a JS return value."""
+    row = _strip_comments((TEMPLATES / "_speaker_row.html").read_text())
+    assert 'onsubmit="return' not in row, (
+        "_speaker_row.html uses onsubmit=\"return ...\"; if that handler ever "
+        "returns a falsy value the browser drops the edit without any error"
+    )
+
+
+def test_every_onsubmit_return_handler_returns_a_boolean() -> None:
+    """Repo-wide: any onsubmit returning a value must decide explicitly."""
+    text = _all_template_text()
+    bodies = _function_bodies(text)
+    for name in sorted(set(ONSUBMIT_RETURN.findall(text))):
+        assert name in bodies, f"onsubmit returns {name}() but it is not defined"
+        body = bodies[name]
+        returns_bool = re.search(r"return\s+(true|false)\b", body)
+        assert returns_bool, (
+            f"onsubmit=\"return {name}(...)\" but {name}() never returns an "
+            "explicit true/false - falling off the end yields undefined, which "
+            "cancels the submit and silently discards the user's edit"
+        )
+
+
+def test_voice_regen_on_save_is_not_empty() -> None:
+    """The specific function that was gutted."""
+    bodies = _function_bodies((TEMPLATES / "speakers.html").read_text())
+    assert "queueVoiceRegenOnSave" in bodies, "handler is missing entirely"
+    body = bodies["queueVoiceRegenOnSave"].strip()
+    assert body, "queueVoiceRegenOnSave has an empty body"
+    assert "enqueueVoice" in body, "it must actually queue a regeneration"
+
+
+def test_edit_form_queues_regen_after_a_successful_save() -> None:
+    """Re-voice must run after the new profile is persisted, not before."""
+    row = _strip_comments((TEMPLATES / "_speaker_row.html").read_text())
+    assert "queueVoiceRegenOnSave" in row
+    assert "hx-on::after-request" in row, (
+        "regeneration should be hooked to after-request so the saved profile "
+        "is on disk before the voice is rebuilt from it"
+    )

umbraaudio/web/templates/_speaker_row.html

@@ -171,7 +171,13 @@
             <form hx-put="/api/speakers/{{ speaker_idx }}"
                   hx-target="#speaker-row-{{ speaker_idx }}"
                   hx-swap="outerHTML"
-                  onsubmit="return queueVoiceRegenOnSave({{ speaker_idx }}, '{{ speaker.primary_name|e }}')">
+                  hx-on::after-request="if(event.detail.successful){ queueVoiceRegenOnSave({{ speaker_idx }}); }">
+                {# Re-voice is hooked to after-request, NOT onsubmit. An
+                   onsubmit="return fn(...)" whose fn falls through returns
+                   undefined, which is falsy, so the browser cancels the whole
+                   submit and silently discards every edit. Queueing here also
+                   guarantees the saved profile is on disk before the voice is
+                   regenerated from it. #}
                 <div style="display:grid; grid-template-columns:1fr 1fr 1fr 1fr; gap:0.5rem; margin-bottom:0.5rem">
                     <input type="text" name="primary_name" value="{{ speaker.primary_name }}" required
                            style="padding:0.4rem; background:#1a1a2e; border:1px solid #333; border-radius:3px; color:#e0e0e0; font-size:0.85rem">

umbraaudio/web/templates/speakers.html

@@ -33,7 +33,18 @@
 var _regenPoll = null;
 var _regenIdx = null;
 
-function queueVoiceRegenOnSave(idx, name) {
+// Runs after a successful PUT, so speakers.json already holds the new profile.
+// The name is re-read from the swapped row because the reviewer may have just
+// renamed the speaker, and regenerating under the old name would voice a
+// speaker that no longer exists.
+function queueVoiceRegenOnSave(idx) {
+    var row = document.getElementById('speaker-row-' + idx);
+    var label = row ? row.querySelector('strong') : null;
+    var name = label ? label.textContent.trim() : '';
+    if (!name) {
+        return;
+    }
+    enqueueVoice(name, idx);
 }
 
 // Voice regeneration is queue-driven (see enqueueVoice below); the old