feat(uploads): choose the language of a recording; record it, show it, carry it to the engines (#61)

Form field (Swedish preselected, Other = auto) read before the file part and refused
before anything is spooled if outside the closed set; stored on the row (migration 021,
CHECK constraint, default sv for history); carried on the Job and the worker's context;
shown on the status page. Feature scenarios and the coverage map are updated, and
ADR-033/034 amended.

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

internal/web/uploads.templ

@@ -24,6 +24,14 @@ templ UploadsPage(v uploadsView) {
 			}
 			<form method="post" action="/uploads" enctype="multipart/form-data">
 				<p><label>Title (optional) <input type="text" name="title" maxlength="200"/></label></p>
+				<p>
+					<label>Language
+						<select name="language">
+							<option value="sv" selected>Swedish</option>
+							<option value="auto">Other (detected by the engine)</option>
+						</select>
+					</label>
+				</p>
 				<p><input type="file" name="file" accept="audio/*,.m4a,.mp3,.wav,.opus,.ogg,.mp4" required/></p>
 				<p><button type="submit">Upload and transcribe</button></p>
 			</form>
@@ -66,6 +74,7 @@ templ uploadStatus(u domain.UploadedTranscript, chatEnabled bool, now time.Time)
 					Transcribed { uploads.FormatDuration(time.Duration(u.AudioSeconds * float64(time.Second))) }
 					of audio by <span class="chip">{ u.Endpoint }</span>.
 				</p>
+				<p>Language: { languageLabel(u.Language) }</p>
 				if provider, cloud := cloudProvider(u.Endpoint); cloud {
 					<p class="cloud-note">
 						This recording's audio left the homelab: it was transcribed by a cloud service ({ provider })