Step 5 piece 6: migrate 23 .sx files to define-library/import

Wraps all core .sx files in R7RS define-library with explicit export
lists, plus (import ...) at end for backward-compatible global re-export.

Libraries registered:
  (sx bytecode)      — 83 opcode constants
  (sx render)        — 15 tag registries + render helpers
  (sx signals)       — 23 reactive signal primitives
  (sx r7rs)          — 21 R7RS aliases
  (sx compiler)      — 42 compiler functions
  (sx vm)            — 32 VM functions
  (sx freeze)        — 9 freeze/thaw functions
  (sx content)       — 6 content store functions
  (sx callcc)        — 1 call/cc wrapper
  (sx highlight)     — 13 syntax highlighting functions
  (sx stdlib)        — 47 stdlib functions
  (sx swap)          — 13 swap algebra functions
  (sx render-trace)  — 8 render trace functions
  (sx harness)       — 21 test harness functions
  (sx canonical)     — 12 canonical serialization functions
  (web adapter-html) — 13 HTML renderer functions
  (web adapter-sx)   — 13 SX wire format functions
  (web engine)       — 33 hypermedia engine functions
  (web request-handler) — 4 request handling functions
  (web page-helpers) — 12 page helper functions
  (web router)       — 36 routing functions
  (web deps)         — 19 dependency analysis functions
  (web orchestration) — 59 page orchestration functions

Key changes:
- define-library now inherits parent env (env-extend env instead of
  env-extend make-env) so library bodies can access platform primitives
- sx_server.ml: added resolve_library_path + load_library_file for
  import resolution (maps library specs to file paths)
- cek_run_with_io: handles "import" locally instead of sending to
  Python bridge

2608/2608 tests passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/orchestration.sx

@@ -1,3 +1,68 @@
+
+
+(define-library (web orchestration)
+  (export
+    _preload-cache
+    dispatch-trigger-events
+    execute-request
+    do-fetch
+    handle-fetch-success
+    flush-collected-styles
+    handle-sx-response
+    handle-html-response
+    handle-retry
+    bind-triggers
+    bind-event
+    post-swap
+    process-settle-hooks
+    activate-scripts
+    process-oob-swaps
+    hoist-head-elements
+    process-boosted
+    boost-descendants
+    _page-data-cache
+    _page-data-cache-ttl
+    page-data-cache-key
+    page-data-cache-get
+    page-data-cache-set
+    invalidate-page-cache
+    invalidate-all-page-cache
+    update-page-cache
+    process-cache-directives
+    _optimistic-snapshots
+    optimistic-cache-update
+    optimistic-cache-revert
+    optimistic-cache-confirm
+    submit-mutation
+    _is-online
+    _offline-queue
+    offline-is-online?
+    offline-set-online!
+    offline-queue-mutation
+    offline-sync
+    offline-pending-count
+    offline-aware-mutation
+    current-page-layout
+    swap-rendered-content
+    resolve-route-target
+    deps-satisfied?
+    try-client-route
+    bind-client-route-link
+    process-sse
+    bind-sse
+    bind-sse-swap
+    bind-inline-handlers
+    bind-preload-for
+    do-preload
+    VERB_SELECTOR
+    process-elements
+    process-one
+    process-emit-elements
+    save-scroll-position
+    handle-popstate
+    engine-init)
+  (begin
+
 (define _preload-cache (dict))
 
 (define
@@ -1566,3 +1631,9 @@
   (fn
     ()
     (do (sx-process-scripts nil) (sx-hydrate nil) (process-elements nil))))
+
+
+)) ;; end define-library
+
+;; Re-export to global namespace for backward compatibility
+(import (web orchestration))