Wire deps.sx into both bootstrappers, rebootstrap Python + JS

deps.sx is now a spec module that both bootstrap_py.py and bootstrap_js.py
can include via --spec-modules deps. Platform functions (component-deps,
component-set-deps!, component-css-classes, env-components, regex-find-all,
scan-css-classes) implemented natively in both Python and JS.

- Fix deps.sx: env-get-or → env-get, extract nested define to top-level
- bootstrap_py.py: SPEC_MODULES, PLATFORM_DEPS_PY, mangle entries, CLI arg
- bootstrap_js.py: SPEC_MODULES, PLATFORM_DEPS_JS, mangle entries, CLI arg
- Regenerate sx_ref.py and sx-ref.js with deps module
- deps.py: thin dispatcher (SX_USE_REF=1 → bootstrapped, else fallback)
- scan_components_from_sx now returns ~prefixed names (consistent with spec)

Verified: 541 Python tests pass, JS deps tested with Node.js, both code
paths (fallback + bootstrapped) produce identical results.

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

shared/sx/ref/deps.sx

@@ -8,19 +8,21 @@
 ;; All functions are pure — no IO, no platform-specific operations.
 ;; Each host bootstraps this to native code alongside eval.sx/render.sx.
 ;;
-;; Platform interface (provided by host):
+;; From eval.sx platform (already provided by every host):
 ;;   (type-of x)          → type string
 ;;   (symbol-name s)      → string name of symbol
 ;;   (component-body c)   → unevaluated AST of component body
 ;;   (component-name c)   → string name (without ~)
-;;
-;; Already available from eval.sx platform:
-;;   (type-of x), (symbol-name s)
-;;
-;; New platform functions for deps:
-;;   (component-body c)   → component body AST
-;;   (component-name c)   → component name string
 ;;   (macro-body m)       → macro body AST
+;;   (env-get env k)      → value or nil
+;;
+;; New platform functions for deps (each host implements):
+;;   (component-deps c)       → cached deps list (may be empty)
+;;   (component-set-deps! c d)→ cache deps on component
+;;   (component-css-classes c)→ pre-scanned CSS class list
+;;   (env-components env)     → list of component/macro names in env
+;;   (regex-find-all pat src) → list of capture group 1 matches
+;;   (scan-css-classes src)   → list of CSS class strings from source
 ;; ==========================================================================
 
 
@@ -66,24 +68,26 @@
 ;; Given a component name and an environment, compute all components
 ;; that it can transitively render.  Handles cycles via seen-set.
 
+(define transitive-deps-walk
+  (fn (n seen env)
+    (when (not (contains? seen n))
+      (append! seen n)
+      (let ((val (env-get env n)))
+        (cond
+          (= (type-of val) "component")
+            (for-each (fn (ref) (transitive-deps-walk ref seen env))
+                      (scan-refs (component-body val)))
+          (= (type-of val) "macro")
+            (for-each (fn (ref) (transitive-deps-walk ref seen env))
+                      (scan-refs (macro-body val)))
+          :else nil)))))
+
+
 (define transitive-deps
   (fn (name env)
     (let ((seen (list))
           (key (if (starts-with? name "~") name (str "~" name))))
-
-      (define walk
-        (fn (n)
-          (when (not (contains? seen n))
-            (append! seen n)
-            (let ((val (env-get-or env n nil)))
-              (cond
-                (= (type-of val) "component")
-                  (for-each walk (scan-refs (component-body val)))
-                (= (type-of val) "macro")
-                  (for-each walk (scan-refs (macro-body val)))
-                :else nil)))))
-
-      (walk key)
+      (transitive-deps-walk key seen env)
       (filter (fn (x) (not (= x key))) seen))))
 
 
@@ -101,7 +105,7 @@
   (fn (env)
     (for-each
       (fn (name)
-        (let ((val (env-get-or env name nil)))
+        (let ((val (env-get env name)))
           (when (= (type-of val) "component")
             (component-set-deps! val (transitive-deps name env)))))
       (env-components env))))
@@ -138,7 +142,7 @@
         (fn (name)
           (when (not (contains? all-needed name))
             (append! all-needed name))
-          (let ((val (env-get-or env name nil)))
+          (let ((val (env-get env name)))
             (let ((deps (if (and (= (type-of val) "component")
                                  (not (empty? (component-deps val))))
                           (component-deps val)
@@ -185,7 +189,7 @@
       ;; Collect classes from needed components
       (for-each
         (fn (name)
-          (let ((val (env-get-or env name nil)))
+          (let ((val (env-get env name)))
             (when (= (type-of val) "component")
               (for-each
                 (fn (cls)
@@ -211,7 +215,7 @@
 ;; From eval.sx (already provided):
 ;;   (type-of x)          → type string
 ;;   (symbol-name s)      → string name of symbol
-;;   (env-get-or env k d) → value or default
+;;   (env-get env k)      → value or nil
 ;;
 ;; New for deps.sx (each host implements):
 ;;   (component-body c)       → AST body of component