feat(blog): add markdown blog sourced from a gitea repo

posts are markdown files with yaml frontmatter (title, slug, date;
optional draft/public) in the grenade/blog repo. the worker's new
BlogSource polls the repo — one branch-tip request when nothing
changed — and upserts posts into events with source='blog' and
occurred_at from the frontmatter date, so imported posts keep their
original publish dates and backfill the contribution graph.

- new /v1/blog and /v1/blog/{slug} endpoints over the existing
  EventReader port; drafts stay hidden via the public gate
- new /blog and /blog/:slug routes, nav link, activity-feed entry
  with post icon and filter toggle; relative image srcs resolve to
  gitea raw urls
- shared Markdown component extracted from ProjectPage
- vite proxy target overridable via API_PROXY_TARGET for local dev

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/moments-core/src/presentation.rs

@@ -5,6 +5,7 @@
 
 use moments_entities::{Event, Source, TimelineItem};
 
+pub mod blog;
 mod bugzilla;
 mod gitea;
 mod github;
@@ -16,5 +17,6 @@ pub fn reshape(event: &Event) -> TimelineItem {
         Source::Gitea => gitea::reshape(event),
         Source::Hg => hg::reshape(event),
         Source::Bugzilla => bugzilla::reshape(event),
+        Source::Blog => blog::reshape(event),
     }
 }

crates/moments-core/src/presentation/blog.rs

@@ -0,0 +1,138 @@
+use moments_entities::{Event, Source, TimelineBody, TimelineIcon, TimelineItem, TitleSegment};
+use serde_json::Value;
+
+const EXCERPT_MAX_CHARS: usize = 280;
+
+pub(crate) fn reshape(event: &Event) -> TimelineItem {
+    let p = &event.payload;
+    let title_text = p
+        .get("title")
+        .and_then(Value::as_str)
+        .unwrap_or("(untitled post)");
+    let slug = p.get("slug").and_then(Value::as_str).unwrap_or("");
+    let markdown = p.get("markdown").and_then(Value::as_str).unwrap_or("");
+
+    let title = vec![
+        TitleSegment::text("published "),
+        TitleSegment::link(title_text, format!("/blog/{slug}")),
+    ];
+
+    let summary = excerpt(markdown);
+    let body = (!summary.is_empty()).then_some(TimelineBody::Markdown { text: summary });
+
+    TimelineItem {
+        id: event.id.clone(),
+        source: Source::Blog,
+        action: event.action.clone(),
+        occurred_at: event.occurred_at,
+        icon: TimelineIcon::Post,
+        title,
+        subtitle: None,
+        body,
+    }
+}
+
+/// First paragraph of prose from a markdown document — skips headings,
+/// images, and other block furniture — truncated on a word boundary.
+/// Reused by the API for `GET /v1/blog` summaries.
+pub fn excerpt(markdown: &str) -> String {
+    let para = markdown
+        .split("\n\n")
+        .map(str::trim)
+        .find(|block| {
+            !block.is_empty()
+                && !block.starts_with('#')
+                && !block.starts_with("![")
+                && !block.starts_with("```")
+                && !block.starts_with('>')
+                && !block.starts_with("---")
+        })
+        .unwrap_or("");
+    let para = para.replace('\n', " ");
+    if para.chars().count() <= EXCERPT_MAX_CHARS {
+        return para;
+    }
+    let cut: String = para.chars().take(EXCERPT_MAX_CHARS).collect();
+    let trimmed = match cut.rfind(' ') {
+        Some(idx) => &cut[..idx],
+        None => cut.as_str(),
+    };
+    format!("{}…", trimmed.trim_end())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::{TimeZone, Utc};
+    use serde_json::json;
+
+    fn ev() -> Event {
+        Event {
+            id: "blog:last-week".into(),
+            source: Source::Blog,
+            action: "publish_post".into(),
+            occurred_at: Utc.with_ymd_and_hms(2026, 6, 12, 0, 0, 0).unwrap(),
+            public: true,
+            payload: json!({
+                "title": "a watchdog, a torrent tracker, and an unhinged friday",
+                "slug": "last-week",
+                "markdown": "## monday\n\nthe week opened deep in helexa's neuron engine.\n",
+                "_host": "git.lair.cafe",
+                "_repo": "grenade/blog",
+                "_branch": "main",
+            }),
+        }
+    }
+
+    #[test]
+    fn reshape_links_to_blog_route() {
+        let item = reshape(&ev());
+        assert_eq!(item.icon, TimelineIcon::Post);
+        assert_eq!(
+            item.title,
+            vec![
+                TitleSegment::text("published "),
+                TitleSegment::link(
+                    "a watchdog, a torrent tracker, and an unhinged friday",
+                    "/blog/last-week"
+                ),
+            ]
+        );
+        match item.body {
+            Some(TimelineBody::Markdown { ref text }) => {
+                assert_eq!(text, "the week opened deep in helexa's neuron engine.")
+            }
+            other => panic!("expected markdown body, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn excerpt_skips_headings_and_images() {
+        let md = "# title\n\n![alt](img.jpg)\n\nfirst real paragraph\nwith a wrapped line\n\nsecond";
+        assert_eq!(excerpt(md), "first real paragraph with a wrapped line");
+    }
+
+    #[test]
+    fn excerpt_truncates_on_word_boundary() {
+        let long: String = (1..=100)
+            .map(|i| format!("w{i}"))
+            .collect::<Vec<_>>()
+            .join(" ");
+        let e = excerpt(&long);
+        assert!(e.chars().count() <= EXCERPT_MAX_CHARS + 1);
+        assert!(e.ends_with('…'));
+        let prefix = e.trim_end_matches('…');
+        assert!(long.starts_with(prefix), "excerpt must be a prefix: {e}");
+        assert_eq!(
+            long.as_bytes()[prefix.len()],
+            b' ',
+            "cut should land on a word boundary: {e}"
+        );
+    }
+
+    #[test]
+    fn excerpt_of_empty_or_heading_only_doc_is_empty() {
+        assert_eq!(excerpt(""), "");
+        assert_eq!(excerpt("# only a heading\n"), "");
+    }
+}