Add following/followers lists and per-actor timeline pages

- 6 new routes: following list, followers list, actor timeline (each
  with HTMX infinite-scroll page endpoint)
- 4 new templates: following.html, followers.html, _actor_list_items.html,
  actor_timeline.html
- Nav links for Following/Followers in base.html
- Follow/unfollow redirects back to referrer page
- Timeline items template handles actor timeline type
- Update shared submodule

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bp/social/routes.py

@@ -157,7 +157,7 @@ def register(url_prefix="/social"):
             await services.federation.send_follow(
                 g.s, actor.preferred_username, remote_actor_url,
             )
-        return redirect(url_for("social.search"))
+        return redirect(request.referrer or url_for("social.search"))
 
     @bp.post("/unfollow")
     async def unfollow():
@@ -168,7 +168,7 @@ def register(url_prefix="/social"):
             await services.federation.unfollow(
                 g.s, actor.preferred_username, remote_actor_url,
             )
-        return redirect(url_for("social.search"))
+        return redirect(request.referrer or url_for("social.search"))
 
     # -- Interactions ---------------------------------------------------------
 
@@ -267,6 +267,138 @@ def register(url_prefix="/social"):
             actor=actor,
         )
 
+    # -- Following / Followers ------------------------------------------------
+
+    @bp.get("/following")
+    async def following_list():
+        actor = _require_actor()
+        actors, total = await services.federation.get_following(
+            g.s, actor.preferred_username,
+        )
+        return await render_template(
+            "federation/following.html",
+            actors=actors,
+            total=total,
+            page=1,
+            actor=actor,
+        )
+
+    @bp.get("/following/page")
+    async def following_list_page():
+        actor = _require_actor()
+        page = request.args.get("page", 1, type=int)
+        actors, total = await services.federation.get_following(
+            g.s, actor.preferred_username, page=page,
+        )
+        return await render_template(
+            "federation/_actor_list_items.html",
+            actors=actors,
+            total=total,
+            page=page,
+            list_type="following",
+            followed_urls=set(),
+            actor=actor,
+        )
+
+    @bp.get("/followers")
+    async def followers_list():
+        actor = _require_actor()
+        actors, total = await services.federation.get_followers_paginated(
+            g.s, actor.preferred_username,
+        )
+        # Build set of followed actor URLs to show Follow Back vs Unfollow
+        following, _ = await services.federation.get_following(
+            g.s, actor.preferred_username, page=1, per_page=1000,
+        )
+        followed_urls = {a.actor_url for a in following}
+        return await render_template(
+            "federation/followers.html",
+            actors=actors,
+            total=total,
+            page=1,
+            followed_urls=followed_urls,
+            actor=actor,
+        )
+
+    @bp.get("/followers/page")
+    async def followers_list_page():
+        actor = _require_actor()
+        page = request.args.get("page", 1, type=int)
+        actors, total = await services.federation.get_followers_paginated(
+            g.s, actor.preferred_username, page=page,
+        )
+        following, _ = await services.federation.get_following(
+            g.s, actor.preferred_username, page=1, per_page=1000,
+        )
+        followed_urls = {a.actor_url for a in following}
+        return await render_template(
+            "federation/_actor_list_items.html",
+            actors=actors,
+            total=total,
+            page=page,
+            list_type="followers",
+            followed_urls=followed_urls,
+            actor=actor,
+        )
+
+    @bp.get("/actor/<int:id>")
+    async def actor_timeline(id: int):
+        actor = getattr(g, "_social_actor", None)
+        # Get remote actor info
+        from shared.models.federation import RemoteActor
+        from sqlalchemy import select as sa_select
+        remote = (
+            await g.s.execute(
+                sa_select(RemoteActor).where(RemoteActor.id == id)
+            )
+        ).scalar_one_or_none()
+        if not remote:
+            abort(404)
+        from shared.services.federation_impl import _remote_actor_to_dto
+        remote_dto = _remote_actor_to_dto(remote)
+        items = await services.federation.get_actor_timeline(g.s, id)
+        # Check if we follow this actor
+        is_following = False
+        if actor:
+            from shared.models.federation import APFollowing
+            existing = (
+                await g.s.execute(
+                    sa_select(APFollowing).where(
+                        APFollowing.actor_profile_id == actor.id,
+                        APFollowing.remote_actor_id == id,
+                    )
+                )
+            ).scalar_one_or_none()
+            is_following = existing is not None
+        return await render_template(
+            "federation/actor_timeline.html",
+            remote_actor=remote_dto,
+            items=items,
+            is_following=is_following,
+            actor=actor,
+        )
+
+    @bp.get("/actor/<int:id>/timeline")
+    async def actor_timeline_page(id: int):
+        actor = getattr(g, "_social_actor", None)
+        before_str = request.args.get("before")
+        before = None
+        if before_str:
+            try:
+                before = datetime.fromisoformat(before_str)
+            except ValueError:
+                pass
+        items = await services.federation.get_actor_timeline(
+            g.s, id, before=before,
+        )
+        return await render_template(
+            "federation/_timeline_items.html",
+            items=items,
+            timeline_type="actor",
+            actor_id=id,
+            actor=actor,
+        )
+
     # -- Notifications --------------------------------------------------------
 
     @bp.get("/notifications")