Send all responses as sexp wire format with client-side rendering

- Server sends sexp source text, client (sexp.js) renders everything
- SexpExpr marker class for nested sexp composition in serialize()
- sexp_page() HTML shell with data-mount="body" for full page loads
- sexp_response() returns text/sexp for OOB/partial responses
- ~app-body layout component replaces ~app-layout (no raw!)
- ~rich-text is the only component using raw! (for CMS HTML content)
- Fragment endpoints return text/sexp, auto-wrapped in SexpExpr
- All _*_html() helpers converted to _*_sexp() returning sexp source
- Head auto-hoist: sexp.js moves meta/title/link/script[ld+json]
  from rendered body to document.head automatically
- Unknown components render warning box instead of crashing page
- Component kwargs preserve AST for lazy rendering (fixes <> in kwargs)
- Fix unterminated paren in events/sexp/tickets.sexpr

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

federation/bp/social/routes.py

@@ -7,6 +7,7 @@ from datetime import datetime
 from quart import Blueprint, request, g, redirect, url_for, abort, Response
 
 from shared.services.registry import services
+from shared.sexp.helpers import sexp_response
 
 log = logging.getLogger(__name__)
 
@@ -58,7 +59,8 @@ def register(url_prefix="/social"):
             g.s, actor.id, before=before,
         )
         from sexp.sexp_components import render_timeline_items
-        return await render_timeline_items(items, "home", actor)
+        sexp_src = await render_timeline_items(items, "home", actor)
+        return sexp_response(sexp_src)
 
     @bp.get("/public")
     async def public_timeline():
@@ -81,7 +83,8 @@ def register(url_prefix="/social"):
         items = await services.federation.get_public_timeline(g.s, before=before)
         actor = getattr(g, "_social_actor", None)
         from sexp.sexp_components import render_timeline_items
-        return await render_timeline_items(items, "public", actor)
+        sexp_src = await render_timeline_items(items, "public", actor)
+        return sexp_response(sexp_src)
 
     # -- Compose --------------------------------------------------------------
 
@@ -158,7 +161,8 @@ def register(url_prefix="/social"):
                 )
                 followed_urls = {a.actor_url for a in following}
         from sexp.sexp_components import render_search_results
-        return await render_search_results(actors, query, page, followed_urls, actor)
+        sexp_src = await render_search_results(actors, query, page, followed_urls, actor)
+        return sexp_response(sexp_src)
 
     @bp.post("/follow")
     async def follow():
@@ -169,7 +173,7 @@ def register(url_prefix="/social"):
             await services.federation.send_follow(
                 g.s, actor.preferred_username, remote_actor_url,
             )
-        if request.headers.get("HX-Request"):
+        if request.headers.get("SX-Request") or request.headers.get("HX-Request"):
             return await _actor_card_response(actor, remote_actor_url, is_followed=True)
         return redirect(request.referrer or url_for("social.search"))
 
@@ -182,7 +186,7 @@ def register(url_prefix="/social"):
             await services.federation.unfollow(
                 g.s, actor.preferred_username, remote_actor_url,
             )
-        if request.headers.get("HX-Request"):
+        if request.headers.get("SX-Request") or request.headers.get("HX-Request"):
             return await _actor_card_response(actor, remote_actor_url, is_followed=False)
         return redirect(request.referrer or url_for("social.search"))
 
@@ -201,7 +205,7 @@ def register(url_prefix="/social"):
         else:
             list_type = "following"
         from sexp.sexp_components import render_actor_card
-        return render_actor_card(remote_dto, actor, followed_urls, list_type=list_type)
+        return sexp_response(render_actor_card(remote_dto, actor, followed_urls, list_type=list_type))
 
     # -- Interactions ---------------------------------------------------------
 
@@ -290,7 +294,7 @@ def register(url_prefix="/social"):
             )).scalar())
 
         from sexp.sexp_components import render_interaction_buttons
-        return render_interaction_buttons(
+        return sexp_response(render_interaction_buttons(
             object_id=object_id,
             author_inbox=author_inbox,
             like_count=like_count,
@@ -298,7 +302,7 @@ def register(url_prefix="/social"):
             liked_by_me=liked_by_me,
             boosted_by_me=boosted_by_me,
             actor=actor,
-        )
+        ))
 
     # -- Following / Followers ------------------------------------------------
 
@@ -321,7 +325,8 @@ def register(url_prefix="/social"):
             g.s, actor.preferred_username, page=page,
         )
         from sexp.sexp_components import render_following_items
-        return await render_following_items(actors, page, actor)
+        sexp_src = await render_following_items(actors, page, actor)
+        return sexp_response(sexp_src)
 
     @bp.get("/followers")
     async def followers_list():
@@ -351,7 +356,8 @@ def register(url_prefix="/social"):
         )
         followed_urls = {a.actor_url for a in following}
         from sexp.sexp_components import render_followers_items
-        return await render_followers_items(actors, page, followed_urls, actor)
+        sexp_src = await render_followers_items(actors, page, followed_urls, actor)
+        return sexp_response(sexp_src)
 
     @bp.get("/actor/<int:id>")
     async def actor_timeline(id: int):
@@ -401,7 +407,8 @@ def register(url_prefix="/social"):
             g.s, id, before=before,
         )
         from sexp.sexp_components import render_actor_timeline_items
-        return await render_actor_timeline_items(items, id, actor)
+        sexp_src = await render_actor_timeline_items(items, id, actor)
+        return sexp_response(sexp_src)
 
     # -- Notifications --------------------------------------------------------