feat(config): P3 config batch — group 1 (clean config + plumbing)

Config plumbing for the whole config batch (HtmlConfig + WikiConfig fields,
RawWiki deserialization, From/defaults) plus these behaviors:

- rss_name / rss_max_items: HtmlConfig fields (wired into write_rss in the RSS
  group).
- toc_link_format: build_toc_text emits [[#anchor]] (no description) for 1,
  [[#anchor|title]] for 0.
- generated_links_caption: build_links_text emits [[page|FirstHeading]] from a
  page->heading map (ops::page_captions) when enabled.
- table_reduce_last_col: column_widths clamps the last column to width 1 when
  set; threaded through table_align_edit/table_move_column_edit + commands.
- color_dic now ships a populated default palette (red/green/blue/...).
- commentstring aligned to upstream's no-space `%%%s`.
- auto_chdir (default off): :lcd into the owning wiki root on buffer enter;
  both clients (ftplugin.lua setup_auto_chdir + Vim NuwikiAutoChdir augroup),
  with config.wiki_root_for / nuwiki#commands#wiki_root_for resolvers.

Also seeded HtmlConfig fields for later groups (valid_html_tags,
list/text_ignore_newline, emoji_enable, user_htmls, color_tag_template) and
WikiConfig (create_link, dir_link, bullet_types, cycle_bullets).

Tests: toc_link_format, generated_links_caption, table_reduce_last_col,
config defaults + JSON round-trip for every new key. Full rust suite +
both keymap harnesses green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/nuwiki-lsp/tests/commands_tables.rs

@@ -45,7 +45,7 @@ fn blank_table_handles_single_cell_grid() {
 fn align_pads_short_cells_to_widest() {
     let src = "|a|bbb|c|\n|--|--|--|\n|1|2|three|\n";
     let ast = parse(src);
-    let edit = ops::table_align_edit(src, &ast, &uri(), 0, true).expect("edit");
+    let edit = ops::table_align_edit(src, &ast, &uri(), 0, true, false).expect("edit");
     let body = one_text(edit);
     let lines: Vec<&str> = body.lines().collect();
     eprintln!("rendered table:");
@@ -64,7 +64,23 @@ fn align_pads_short_cells_to_widest() {
 fn align_returns_none_when_cursor_off_table() {
     let src = "paragraph\n";
     let ast = parse(src);
-    assert!(ops::table_align_edit(src, &ast, &uri(), 0, true).is_none());
+    assert!(ops::table_align_edit(src, &ast, &uri(), 0, true, false).is_none());
+}
+
+#[test]
+fn table_reduce_last_col_keeps_last_column_minimal() {
+    // With reduce_last_col=true, the last column isn't padded to its content
+    // width — it stays at the minimum (1), so `three` is not surrounded by
+    // alignment padding on the right edge.
+    let src = "|a|bbb|c|\n|--|--|--|\n|1|2|three|\n";
+    let ast = parse(src);
+    let edit = ops::table_align_edit(src, &ast, &uri(), 0, true, true).expect("edit");
+    let body = one_text(edit);
+    let lines: Vec<&str> = body.lines().collect();
+    // First two columns still align; the last column stays at width 1 (not 5),
+    // so the header's last cell renders `| c |` not `| c     |`.
+    assert_eq!(lines[0], "| a | bbb | c |", "got: {:?}", lines[0]);
+    assert_eq!(lines[2], "| 1 | 2   | three |", "got: {:?}", lines[2]);
 }
 
 // ===== moveColumn =====
@@ -74,7 +90,7 @@ fn move_column_right_swaps_with_neighbour() {
     let src = "|a|b|c|\n|--|--|--|\n|1|2|3|\n";
     let ast = parse(src);
     // Cursor on first column → swap right.
-    let edit = ops::table_move_column_edit(src, &ast, &uri(), 0, 1, 1, true).expect("edit");
+    let edit = ops::table_move_column_edit(src, &ast, &uri(), 0, 1, 1, true, false).expect("edit");
     let body = one_text(edit);
     let lines: Vec<&str> = body.lines().collect();
     assert!(lines[0].contains("b") && lines[0].contains("a"));
@@ -90,7 +106,7 @@ fn move_column_left_at_zero_is_noop() {
     let src = "|a|b|\n|--|--|\n|1|2|\n";
     let ast = parse(src);
     // Cursor in column 0; left would be -1 → returns None.
-    let edit = ops::table_move_column_edit(src, &ast, &uri(), 0, 1, -1, true);
+    let edit = ops::table_move_column_edit(src, &ast, &uri(), 0, 1, -1, true, false);
     assert!(edit.is_none());
 }
 
@@ -98,7 +114,7 @@ fn move_column_left_at_zero_is_noop() {
 fn move_column_returns_none_off_table() {
     let src = "paragraph\n";
     let ast = parse(src);
-    assert!(ops::table_move_column_edit(src, &ast, &uri(), 0, 0, 1, true).is_none());
+    assert!(ops::table_move_column_edit(src, &ast, &uri(), 0, 0, 1, true, false).is_none());
 }
 
 // ===== COMMANDS list =====