fix(ci): add missing roxygen param and guard snic chunks in Quarto

- Add @PARAM original_canvas_size to render_image_filled_pieces() roxygen
  and .Rd file, fixing R-CMD-check WARNING on all platforms
- Add eval: !expr has_snic guards to demo-snic-ggpuzzle and demo-snic-api
  chunks, fixing Quarto Publish failure when snic package is unavailable
- Update snic-image-usage chunk to use bundled sample_image.jpg instead
  of placeholder "photo.jpg", enabling live evaluation (closes #120)

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

Author: pjt222

R/image_fill_rendering.R

@@ -81,6 +81,8 @@ render_image_clip_defs <- function(pieces) {
 #' @param opacity Piece opacity (0.0 to 1.0)
 #' @param image_width Original image width in pixels
 #' @param image_height Original image height in pixels
+#' @param original_canvas_size Original canvas size before offset expansion,
+#'   used to size the clipped image correctly. If NULL, uses canvas_size.
 #' @return Character vector of SVG group elements
 #'
 #' @keywords internal

man/render_image_filled_pieces.Rd

@@ -298,23 +298,23 @@ When provided with an image, SNIC creates pieces that follow the image's visual
 
 ```{r}
 #| label: snic-image-usage
-#| eval: false
-library(jigsawR)
+#| eval: !expr has_snic
+#| fig-align: center
+
+# Use the package's bundled sample image
+sample_image <- system.file("extdata", "sample_image.jpg", package = "jigsawR")
 
 # Generate SNIC puzzle from an image
 result <- generate_puzzle(
   type = "snic",
   grid = c(30),
   size = c(300, 400),
   seed = 42,
-  image_path = "photo.jpg",   # Path to your image
+  image_path = sample_image,
   compactness = 0.5,
   seed_type = "hexagonal"
 )
 
-# Save SVG
-writeLines(result$svg_content, "snic_puzzle.svg")
-
 # Preview
 render_puzzle_preview(result)
 ```
@@ -347,6 +347,7 @@ Image-based SNIC puzzles adapt piece boundaries to follow edges and features in
 
 ```{r}
 #| label: demo-snic-ggpuzzle
+#| eval: !expr has_snic
 #| fig-align: center
 
 ggplot() +
@@ -368,6 +369,7 @@ ggplot() +
 
 ```{r}
 #| label: demo-snic-api
+#| eval: !expr has_snic
 #| fig-align: center
 
 # Generate puzzle