Refactor analysis display to full HTML

Replaces `analysis_preview` with `analysis_html` to display the full
markdown-rendered document content instead of just a plain-text preview.
This allows for richer content presentation and enables client-side
expansion for detailed views.

The HTML template has been updated to include a new `.analysis`
container that handles the expand/collapse functionality using
JavaScript. This approach avoids server-side truncation and relies on
CSS for presentation.

server/src/routes/user_web.rs

@@ -91,11 +91,12 @@ struct UserCaseView {
     /// "geschlossen"). Clamped at 0 — cases eligible for purge this
     /// sweep render as "0" briefly.
     days_until_purge: Option<u32>,
-    /// First paragraph of `document.md` as plain text (markdown
-    /// formatting stripped). `None` when the case has no document yet.
-    /// The browser CSS-clamps this to the user's configured number of
-    /// lines; no server-side line counting happens.
-    analysis_preview: Option<String>,
+    /// Full `document.md` rendered through the same `md_to_html`
+    /// pipeline as the case-detail page. `None` when the case has no
+    /// document yet. The browser clamps this to `preview_lines` in the
+    /// collapsed state and shows it whole when expanded — single
+    /// rendering, two CSS layouts, no server-side truncation.
+    analysis_html: Option<String>,
 }
 
 /// Parse a recording filename `YYYY-MM-DDTHH-MM-SSZ.m4a[.failed]` as UTC
@@ -243,30 +244,6 @@ fn recorded_at_iso_of(filename: &str) -> String {
         .unwrap_or_default()
 }
 
-/// Extract the first paragraph of a `document.md` body as plain text.
-///
-/// A "paragraph" here is the first non-empty block separated by a blank
-/// line (`\n\n`). Markdown decoration characters (`#`, `*`, `_`, `` ` ``,
-/// `=`, `>`) are stripped — the preview is meant to appear in a cramped
-/// list row where bold/italic/heading styling would only add noise.
-/// Returns `None` for input that ends up blank after stripping.
-///
-/// The visible line count is NOT enforced here: that is browser-side via
-/// CSS `line-clamp`. Server logic stays viewport-agnostic.
-fn preview_from_markdown(md: &str) -> Option<String> {
-    let first = md.split("\n\n").map(str::trim).find(|p| !p.is_empty())?;
-    let plain: String = first
-        .chars()
-        .filter(|c| !matches!(c, '#' | '*' | '_' | '`' | '=' | '>'))
-        .collect();
-    let trimmed = plain.trim();
-    if trimmed.is_empty() {
-        None
-    } else {
-        Some(trimmed.to_string())
-    }
-}
-
 struct DateGroup {
     /// "Heute", "Gestern", or ISO date "YYYY-MM-DD".
     label: String,
@@ -904,10 +881,12 @@ async fn compute_case_view(
     // One extra read per case with a document. Documents are in the KB
     // range — negligible next to the existing scan_recordings I/O — and
     // we skip the read entirely when the stat above said no document.
-    let analysis_preview = if has_document {
+    // Rendered once, regardless of expand state: the browser handles
+    // clamp-vs-expand purely through CSS toggling.
+    let analysis_html = if has_document {
         read_document(case_path)
             .await
-            .and_then(|md| preview_from_markdown(&md))
+            .map(|md| crate::analyze::render::md_to_html(&md))
     } else {
         None
     };
@@ -927,7 +906,7 @@ async fn compute_case_view(
         can_analyze,
         is_closed,
         days_until_purge,
-        analysis_preview,
+        analysis_html,
     })
 }
 
@@ -1017,62 +996,6 @@ async fn compute_oneliner_display(
 mod tests {
     use super::*;
 
-    #[test]
-    fn preview_from_markdown_takes_first_paragraph() {
-        let md = "Erster Absatz mit Text.\n\nZweiter Absatz, irrelevant.";
-        assert_eq!(
-            preview_from_markdown(md).as_deref(),
-            Some("Erster Absatz mit Text.")
-        );
-    }
-
-    #[test]
-    fn preview_from_markdown_strips_formatting_chars() {
-        let md = "# Überschrift\n\n**Patient** klagt über _Knie_ mit ==Schmerz==.";
-        // Both the heading and the inline formatting survive only as plain text.
-        assert_eq!(preview_from_markdown(md).as_deref(), Some("Überschrift"));
-    }
-
-    #[test]
-    fn preview_from_markdown_skips_leading_blank_paragraphs() {
-        let md = "\n\n\n\nErster echter Absatz.";
-        assert_eq!(
-            preview_from_markdown(md).as_deref(),
-            Some("Erster echter Absatz.")
-        );
-    }
-
-    #[test]
-    fn preview_from_markdown_returns_none_for_blank_input() {
-        assert_eq!(preview_from_markdown(""), None);
-        assert_eq!(preview_from_markdown("   \n\n   "), None);
-    }
-
-    #[test]
-    fn preview_from_markdown_returns_none_when_only_formatting() {
-        // An all-formatting "paragraph" (no actual letters/numbers after
-        // strip) should collapse to None rather than an empty preview row.
-        assert_eq!(preview_from_markdown("=== ## **"), None);
-    }
-
-    #[test]
-    fn preview_from_markdown_strips_inline_formatting_but_keeps_words() {
-        let md = "**Fett** und _kursiv_ und `code` in einer Zeile.";
-        assert_eq!(
-            preview_from_markdown(md).as_deref(),
-            Some("Fett und kursiv und code in einer Zeile.")
-        );
-    }
-
-    #[test]
-    fn preview_from_markdown_drops_blockquote_marker() {
-        let md = "> Patient berichtet über Schmerzen.";
-        assert_eq!(
-            preview_from_markdown(md).as_deref(),
-            Some("Patient berichtet über Schmerzen.")
-        );
-    }
-
     fn mk_view(most_recent: &str, is_closed: bool) -> UserCaseView {
         UserCaseView {
             case_id: "00000000-0000-0000-0000-000000000000".into(),
@@ -1087,7 +1010,7 @@ mod tests {
             can_analyze: false,
             is_closed,
             days_until_purge: None,
-            analysis_preview: None,
+            analysis_html: None,
         }
     }