Add serverless IPFS applications to SX-Activity plan

Entire web applications as content-addressed SX on IPFS — no server,
no DNS, no hosting, no deployment pipeline. Server becomes an optional
IO provider, not an application host. The application is the content.

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

sx/sx/plans.sx

@@ -469,7 +469,25 @@
               (tr :class "border-b border-stone-100"
                 (td :class "px-3 py-2 text-stone-700" "Trust-based package security")
                 (td :class "px-3 py-2 text-stone-700" "Structural sandboxing")
-                (td :class "px-3 py-2 text-stone-600" "Pure functions can't have side effects — not by policy, by construction"))))))
+                (td :class "px-3 py-2 text-stone-600" "Pure functions can't have side effects — not by policy, by construction"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 text-stone-700" "Servers + hosting + DNS + TLS")
+                (td :class "px-3 py-2 text-stone-700" "IPFS CID")
+                (td :class "px-3 py-2 text-stone-600" "Entire applications are content-addressed, no infrastructure needed"))))))
+
+      (~doc-subsection :title "Serverless applications on IPFS"
+        (p "The logical conclusion: " (strong "entire web applications hosted on IPFS with no server at all."))
+        (p "An SX application is a tree of content-addressed artifacts: a root page definition, component dependencies, media, stylesheets, parsers, transforms. Pin the root CID to IPFS and the application is live. No server, no DNS, no hosting provider, no deployment pipeline. Someone gives you a CID, you paste it into an SX-aware browser, and the application runs.")
+        (~doc-code :code (highlight ";; An entire blog — one CID\n;; ipfs://bafy...my-blog\n(defpage blog-home\n  :path \"/\"\n  :requires (list\n    \"bafy...article-layout\"    ;; layout component\n    \"bafy...md-parser\"         ;; markdown parser\n    \"bafy...syntax-highlight\"  ;; code highlighting\n    \"bafy...nav-component\")    ;; navigation\n  :content\n    (~article-layout\n      :title \"My Blog\"\n      :nav (~nav-component\n        :items (list\n          (dict :label \"Post 1\" :cid \"bafy...post-1\")\n          (dict :label \"Post 2\" :cid \"bafy...post-2\")))\n      :body (~markdown-page\n        :source-cid \"bafy...homepage-md\")))" "lisp"))
+        (p "What this looks like in practice:")
+        (ul :class "list-disc pl-5 text-stone-700 space-y-1"
+          (li (strong "Personal sites: ") "A portfolio or blog is a handful of SX files + media. Pin to IPFS. Share the CID. No hosting costs, no domain renewal, no SSL certificates. The site is permanent.")
+          (li (strong "Documentation: ") "Pin your docs. They can't go offline, can't be censored, can't be altered after publication (provenance proves it). Anyone can mirror them by pinning the same CID.")
+          (li (strong "Collaborative applications: ") "Multiple authors contribute pages and components. Each publishes their CIDs. A root manifest composes them. Update the manifest CID to add content — old CIDs remain valid forever.")
+          (li (strong "Offline-first: ") "An IPFS-hosted app works the same whether you're online or have the content cached locally. The browser's SX evaluator + local IPFS node = complete offline platform.")
+          (li (strong "Zero-cost deployment: ") "\"Deploying\" means computing a hash. No CI/CD, no Docker, no cloud provider. Pin locally, pin to a remote IPFS node, or let others pin if they want to help host."))
+        (p "For applications that " (em "do") " need a server — user accounts, payments, real-time collaboration, database queries — the server provides IO primitives via the existing boundary system. The SX application fetches data from the server's IO endpoints, but the application itself (all the rendering, routing, component logic) lives on IPFS. The server is a " (em "data service") ", not an application host.")
+        (p "This inverts the current model. Today: server hosts the application, client is a thin renderer. SX web: IPFS hosts the application, server is an optional IO provider. " (strong "The application is the content. The content is the application. Both are just s-expressions.")))
 
       (~doc-subsection :title "The end state"
         (p "A browser with an SX evaluator and an IPFS gateway is a complete web platform. Given a CID — for a page, a post, an application — it can:")