Fix post-feed.html: recursive reply fetching for nested replies

Replies to replies don't carry the root post ID in their e tags, only their
immediate parent's ID. The old single-level #e filter missed nested replies.

Added fetchRepliesRecursive() which does breadth-first recursive fetching:
- Starts with root post ID, fetches direct replies
- For each reply found, fetches replies to THAT reply
- Continues up to 5 levels deep (REPLY_FETCH_MAX_DEPTH)
- Deduplicates by event ID
- Per-level timeout (8s) to guard against slow relays
- Real-time handler also triggers 1-level recursive fetch for new replies

This matches Amethyst's ThreadFilterAssemblerSubscription approach.

www/js/version.json

@@ -1,5 +1,5 @@
 {
-  "VERSION": "v0.7.27",
-  "VERSION_NUMBER": "0.7.27",
-  "BUILD_DATE": "2026-06-26T00:00:43.641Z"
+  "VERSION": "v0.7.28",
+  "VERSION_NUMBER": "0.7.28",
+  "BUILD_DATE": "2026-06-26T00:20:10.087Z"
 }

www/post-feed.html

@@ -575,8 +575,11 @@
       if (!evt?.tags) return false;
       const eTags = evt.tags.filter((t) => t[0] === 'e' && t[1]);
       if (eTags.length === 0) return false;
-      // A reply is any kind 1 that references the target event id in an e tag.
-      return eTags.some((t) => t[1] === targetEventId);
+      // A reply is any kind 1 that references the root post OR any already-known
+      // reply in the thread (nested replies only carry their immediate parent,
+      // not the root post id). This keeps the thread inclusive of replies-to-replies.
+      if (eTags.some((t) => t[1] === targetEventId)) return true;
+      return eTags.some((t) => replyIds.has(t[1]));
     }
 
     function upsertReply(evt) {
@@ -850,11 +853,6 @@
       }
     }
 
-    function appendReplyIfNew(evt) {
-      if (!upsertReply(evt)) return;
-      renderReplies();
-    }
-
     /* ================================================================
        BOTTOM REPLY COMPOSER
        ================================================================
@@ -964,27 +962,104 @@
       });
     }
 
+    /* ----------------------------------------------------------------
+       fetchRepliesRecursive(rootEventId, maxDepth)
+       ----------------------------------------------------------------
+       Recursively fetches replies to the root post AND replies to those
+       replies (nested replies), up to maxDepth levels. Nested replies
+       only carry their immediate parent in their `e` tags — not the root
+       post id — so a single { '#e': [rootId] } query misses them.
+
+       Strategy (breadth-first by depth level):
+         depth 0: fetch replies to rootEventId
+         depth 1: fetch replies to every reply found at depth 0
+         depth 2: fetch replies to every reply found at depth 1
+         ... up to maxDepth
+
+       The `#e` filter accepts an array of ids, so we batch all ids at
+       the current depth into a single fetch. Dedup via replyIds so a
+       reply discovered via multiple parent paths is only added once.
+
+       Both the cache (queryCache) and relays (ndkFetchEvents) are
+       consulted at each level — cache first for fast display, then
+       relays for hydration. A per-level timeout guards against
+       excessive relay requests on very long threads.
+       ---------------------------------------------------------------- */
+    const REPLY_FETCH_MAX_DEPTH = 5;
+    const REPLY_FETCH_LEVEL_TIMEOUT_MS = 8000;
+
+    function fetchRepliesForLevelFromCache(parentIds) {
+      return queryCache({ kinds: [1], '#e': parentIds }).catch(() => []).then((r) => Array.isArray(r) ? r : []);
+    }
+
+    function fetchRepliesForLevelFromRelays(parentIds) {
+      return new Promise((resolve) => {
+        let settled = false;
+        const timer = setTimeout(() => {
+          if (settled) return;
+          settled = true;
+          resolve([]);
+        }, REPLY_FETCH_LEVEL_TIMEOUT_MS);
+
+        ndkFetchEvents({ kinds: [1], '#e': parentIds })
+          .then((events) => {
+            if (settled) return;
+            settled = true;
+            clearTimeout(timer);
+            resolve(Array.isArray(events) ? events : []);
+          })
+          .catch((error) => {
+            console.warn('[post-feed.html] Recursive reply level fetch failed:', error?.message || error);
+            if (settled) return;
+            settled = true;
+            clearTimeout(timer);
+            resolve([]);
+          });
+      });
+    }
+
+    async function fetchRepliesRecursive(rootEventId, maxDepth = REPLY_FETCH_MAX_DEPTH) {
+      if (!rootEventId) return;
+
+      let currentLevelIds = [rootEventId];
+
+      for (let depth = 0; depth < maxDepth; depth += 1) {
+        if (currentLevelIds.length === 0) break;
+
+        // Cache first — fast display of whatever we already have.
+        const cachedEvents = await fetchRepliesForLevelFromCache(currentLevelIds);
+        const nextLevelIds = [];
+        for (const evt of cachedEvents) {
+          if (upsertReply(evt)) {
+            nextLevelIds.push(evt.id);
+          }
+        }
+        if (cachedEvents.length > 0) renderReplies();
+
+        // Then relay hydration for this level.
+        const relayEvents = await fetchRepliesForLevelFromRelays(currentLevelIds);
+        for (const evt of relayEvents) {
+          if (upsertReply(evt)) {
+            nextLevelIds.push(evt.id);
+          }
+        }
+        if (relayEvents.length > 0) renderReplies();
+
+        // Move to the next depth level: replies to the replies we just found.
+        // (upsertReply dedupes via replyIds, so ids already seen are skipped
+        // on the next iteration by virtue of not being newly added — but we
+        // still need to query for their children, so include all newly-found
+        // ids here.)
+        currentLevelIds = nextLevelIds;
+      }
+
+      // Final render to ensure consistency.
+      renderReplies();
+    }
+
     async function fetchReplies() {
       if (!targetEventId) return;
-
-      // Cache first.
-      try {
-        const cachedReplies = await queryCache({ kinds: [1], '#e': [targetEventId] });
-        if (Array.isArray(cachedReplies)) {
-          cachedReplies.forEach((evt) => upsertReply(evt));
-          renderReplies();
-        }
-      } catch (_) {}
-
-      // Then relay fetch.
-      void ndkFetchEvents({ kinds: [1], '#e': [targetEventId] }).then((fresh) => {
-        if (Array.isArray(fresh)) {
-          fresh.forEach((evt) => upsertReply(evt));
-        }
-        renderReplies();
-      }).catch((error) => {
-        console.warn('[post-feed.html] Reply fetch failed:', error?.message || error);
-      });
+      await fetchRepliesRecursive(targetEventId, REPLY_FETCH_MAX_DEPTH);
     }
 
     /* ================================================================
@@ -1153,7 +1228,16 @@
           }
 
           if (isReplyToThread(evt)) {
-            appendReplyIfNew(evt);
+            const wasNew = upsertReply(evt);
+            if (wasNew) {
+              renderReplies();
+              // A newly-seen reply may itself have nested replies we haven't
+              // fetched yet. Trigger a one-level-deep fetch for replies to it
+              // so nested replies appear in realtime too.
+              fetchRepliesRecursive(evt.id, 1).catch((err) => {
+                console.warn('[post-feed.html] Realtime nested fetch failed:', err?.message || err);
+              });
+            }
           }
         });