feat(13.1): colorize + color_dic → ColorNode renderer

Closes the last pending §13.1 entries:

- **`nuwiki.colorize`** (client-side, Lua + VimL) — wraps the word
  at cursor (or the visual selection on Neovim) in an inline
  `<span style="color:%c">…</span>` template. Matches vimwiki's
  default `color_tag_template`. Bound to `<Leader>wc` in both
  normal and visual mode on both editor paths; the previous
  "deferred" stub is gone.

- **`color_dic` → renderer** — `HtmlConfig` gains a
  `color_dic: HashMap<String, String>` field reading the same key
  out of `initializationOptions` / `didChangeConfiguration`. The
  HTML export path threads it into `HtmlRenderer::with_colors`;
  `ColorNode` now picks `style="color:<value>"` when the colour
  name is in the dict, falling back to the existing
  `class="color-<name>"` when it isn't.

SPEC §13.1 is fully checked off — the table moved from "deferred
sketch" to a per-command status table marking all 11 commands done,
plus a note on the `color_dic` follow-up landing alongside. README's
"Phase 14 list & table edit commands" row now reads ✅ without the
deferred-subset caveat, and the §13.1-blocked text-objects note in
the keymaps section is rephrased as "planned follow-ups".

Tests: 4 new in `phase17_colorize.rs` covering the renderer
fallback when the dict is empty, the inline-style emission for a
listed name, the fallback path for an unlisted name in a populated
dict, and the `initializationOptions` JSON shape. Total 414 Rust
tests pass; clippy clean; keymap harness still 20/20.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/nuwiki-core/src/render/html.rs

@@ -36,6 +36,11 @@ pub struct HtmlRenderer {
     link_resolver: LinkResolver,
     template: Option<String>,
     vars: HashMap<String, String>,
+    /// `color_dic`-style override: vimwiki colour-tag names → CSS
+    /// values (`"red"` / `"#ffe119"` / `"oklch(…)"`). Unspecified
+    /// names fall through to the default `class="color-<name>"`
+    /// rendering. Matches SPEC §12.11 `color_dic`.
+    colors: HashMap<String, String>,
 }
 
 impl Default for HtmlRenderer {
@@ -50,6 +55,7 @@ impl HtmlRenderer {
             link_resolver: Arc::new(default_link_resolver),
             template: None,
             vars: HashMap::new(),
+            colors: HashMap::new(),
         }
     }
 
@@ -83,6 +89,14 @@ impl HtmlRenderer {
         self.vars = vars;
         self
     }
+
+    /// Supply a `color_dic`: vimwiki colour-tag names mapped to their
+    /// CSS values. A name listed here is rendered as `style="color:V"`;
+    /// missing names fall through to `class="color-<name>"`.
+    pub fn with_colors(mut self, colors: HashMap<String, String>) -> Self {
+        self.colors = colors;
+        self
+    }
 }
 
 impl Renderer for HtmlRenderer {
@@ -441,9 +455,15 @@ impl HtmlRenderer {
     }
 
     fn render_color(&self, n: &ColorNode, w: &mut dyn Write) -> io::Result<()> {
-        write!(w, "<span class=\"color-")?;
-        write_escaped(&n.color, w)?;
-        w.write_all(b"\">")?;
+        if let Some(css) = self.colors.get(&n.color) {
+            w.write_all(b"<span style=\"color:")?;
+            write_escaped(css, w)?;
+            w.write_all(b"\">")?;
+        } else {
+            w.write_all(b"<span class=\"color-")?;
+            write_escaped(&n.color, w)?;
+            w.write_all(b"\">")?;
+        }
         self.render_inlines(&n.children, w)?;
         w.write_all(b"</span>")
     }