Recipe detail page with server-side HTML rendering

- Add Roux.Html.recipePage: full recipe detail page with:
  - Back navigation link
  - Title and metadata (servings, times, difficulty, etc.)
  - Ingredients summary list with quantities
  - Sections with named headings
  - Steps with inline element rendering:
    - Ingredients highlighted in pumpkin (with quantity badge)
    - Cookware in violet italic
    - Timers in azure with ⏱ icon
    - Comments in sand italic
    - Recipe refs as links
    - Line breaks
- Update Roux.Server: route /recipes/FILENAME to recipe page
  - Case-insensitive filename lookup, .cook extension optional
  - URL decoding for filenames
- Fix ingredient name parsing: restrict name characters to
  alphaNum + spaces/hyphens/apostrophes, preventing greedy
  consumption across special chars like ) and #
- Split name chars into pMultiNameChar (with spaces, before braces)
  and pSingleNameChar (without spaces, fallback)
- Suppress -Wname-shadowing in Html.hs (blaze-html exports clash
  with common variable names)
- All 26 tests passing, server smoke-tested with examples

src/Roux/Parser.hs

@@ -128,6 +128,10 @@ pLineBreak = do
     _ <- P.newline
     return StepBreak
 
+-- | Characters allowed in recipe reference paths.
+pPathChar :: Parser Char
+pPathChar = P.alphaNum P.<|> P.oneOf "./-_"
+
 -- | Recipe reference: @./path/to/recipe{quantity}
 pRecipeRef :: Parser StepItem
 pRecipeRef = do
@@ -135,7 +139,7 @@ pRecipeRef = do
     -- Consume @ and store ./ as part of the path
     _ <- P.char '.'
     _ <- P.char '/'
-    path <- P.many (P.noneOf "{(\n\\")
+    path <- P.many pPathChar
     mqty <- P.optionMaybe (P.between (P.char '{') (P.char '}') pQuantityBody)
     return (StepRecipeRef (RecipeRef ("./" <> path) (join mqty)))
 
@@ -147,6 +151,14 @@ pIngredient = do
     prep <- P.optionMaybe (P.try pPreparation)
     return (StepIngredient (Ingredient (T.pack name) qty (fmap T.strip prep)))
 
+-- | Characters allowed in names that may include spaces (before braces).
+pMultiNameChar :: Parser Char
+pMultiNameChar = P.alphaNum P.<|> P.oneOf " .-'"
+
+-- | Characters allowed in single-word names (no braces).
+pSingleNameChar :: Parser Char
+pSingleNameChar = P.alphaNum P.<|> P.oneOf ".-'"
+
 {- | Parse a name optionally followed by @{quantity}@ braces.
 
 Used by ingredients.  First tries a multi-word name with braces
@@ -156,14 +168,14 @@ pNameWithQuantity :: Parser ([Char], Maybe Quantity)
 pNameWithQuantity =
     P.try
         ( do
-            name <- P.many (P.noneOf "{(\n\\")
+            name <- P.many pMultiNameChar
             _ <- P.char '{'
             qty <- pQuantityBody
             _ <- P.char '}'
             return (name, qty)
         )
         P.<|> do
-            name <- P.many1 (P.alphaNum P.<|> P.oneOf ".-'")
+            name <- P.many1 pSingleNameChar
             return (name, Nothing)
 
 {- | Parse a name optionally followed by empty @{}@ braces.
@@ -174,12 +186,12 @@ pNameWithBraces :: Parser [Char]
 pNameWithBraces =
     P.try
         ( do
-            name <- P.many (P.noneOf "{(\n\\")
+            name <- P.many pMultiNameChar
             _ <- P.char '{'
             _ <- P.char '}'
             return name
         )
-        P.<|> P.many1 (P.alphaNum P.<|> P.oneOf ".-'")
+        P.<|> P.many1 pSingleNameChar
 
 -- | Parse preparation text inside parentheses: @name(diced)
 pPreparation :: Parser Text