Fix pattern fill rendering bug

Two issues prevented pattern fills from rendering:

1. In ir/lower.clj resolve-fill: the case matched :fill/pattern but
   scene fills arrive as :pattern. Add :pattern as an alias.
   Make resolve-fill public so effect.clj can reuse it.

2. In ir/effect.clj item->base-op: fill resolution only handled
   color vectors and {:r :g :b} maps, silently dropping pattern,
   gradient, and other semantic fills. Delegate to resolve-fill
   for any fill with :fill/type.

This was a pre-existing bug (present since pattern fills were added),
not caused by the namespace restructuring.

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

Author: leifericf

src/eido/ir/effect.clj

@@ -75,9 +75,11 @@
   "Converts a draw item to a concrete op (simplified — for shadow/glow copies).
   Handles basic geometry types with fill, stroke, opacity."
   [geom fill stroke opacity]
-  (let [resolved-fill (when fill
+  (let [resolve-fn   (requiring-resolve 'eido.ir.lower/resolve-fill)
+        resolved-fill (when fill
                         (cond
                           (vector? fill)                          (color/resolve-color fill)
+                          (:fill/type fill)                       (resolve-fn fill)
                           (:color fill)                           (color/resolve-color (:color fill))
                           (and (:r fill) (:g fill) (:b fill))     fill
                           :else                                   nil))

src/eido/ir/lower.clj

@@ -15,7 +15,7 @@
 
 ;; --- fill resolution ---
 
-(defn- resolve-fill
+(defn resolve-fill
   "Resolves a semantic fill descriptor to the format concrete ops expect."
   [f]
   (when f
@@ -34,7 +34,7 @@
         (:gradient/radius f) (assoc :gradient/radius (:gradient/radius f)))
 
       ;; Pattern fill — compile tile nodes to ops
-      :fill/pattern
+      (:fill/pattern :pattern)
       (when-let [tile-nodes (:pattern/nodes f)]
         (let [[tw th] (:pattern/size f)]
           {:fill/type    :pattern