v0.16.0 — Universal trailing-token color syntax

⚠ BREAKING: Universal trailing-token color syntax

Color is now the trailing whitespace-delimited token of a label region
(case-sensitive lowercase, matching one of 11 palette names: red, orange, yellow, green, blue, purple, teal, cyan, gray, black, white). The old
Label(color) parens form is gone — parens are now literal label text.

Done(green)             →  Done green
[Done](green)           →  [Done] green
Swordsmanship(red) as s →  Swordsmanship red as s
era 1718 -> 1720 Foo(red) → era 1718 -> 1720 Foo red

The label region is whatever the parser hands to the color rule after
stripping its own structural terminators (as <alias>, | pipe, numeric
values, date ranges, brackets, arrow constructs). This applies uniformly
across every chart type that carries color in label position.

Capitalize to escape: Red, Yellow, Green stay as literal labels
— useful for traffic-light tag groups that want the color word as the
name itself.

The 11-name palette is now a frozen public contract. Adding a 12th
color name in any future release is itself a breaking grammar change
requiring a major version bump, because any user diagram with the new
word as a label would silently change behavior.

Edge color removed (flowchart, state, sitemap)

Edges on these three chart types no longer have a color slot. A -(red)-> B
parses as a label (red); A -yes-> B and A -no-> B no longer auto-color
the arrow. All edges render with the default theme color. To color a node,
use tags. Sankey/chord links are the one exception — they carry data, so a
trailing color word after the numeric flow value colors the link
(Source -> Target 3000 red).

The inferArrowColor() function (label-semantic yes→green, no→red,
maybe→orange) and matchColorParens() helper are both deleted; their
@diagrammo/dgmo/advanced re-exports are gone.

Cycle / pyramid / ring / RACI / boxes-and-lines: pipe-shortcut

These five chart types pair the universal trailing-token form with their
existing | color: <name> pipe-metadata long form. Both produce the same
AST; the trailing-token form is a shortcut when color is the sole metadata:

Spring green                       // shortcut
Spring | color: green              // long form (equivalent)
Spring | color: green, icon: ❄     // long form REQUIRED when other keys

Accepted tradeoffs

• No typo diagnostics: Done grren parses silently as a 2-word label
  with no color. Internal corpus has a near-miss smoke test; user content
  gets no help.
• Case-sensitivity is the escape hatch: only lowercase recognized.
• Lezer grammar drops the ColorAnnotation token; trailing color
  words now tokenize as plain Identifier nodes.

Changed

• Static exports hide collapsed tag-group pills and the gear/cog control.
  When a diagram is exported (PNG / SVG / PDF) via the desktop or web app,
  the legend now shows only the active tag-group capsule centered above the
  diagram. Collapsed group pills, interactive toggles, and the cog disappear
  — they convey no meaning in a static image. Interactive previews and
  shared online.diagrammo.app views are unchanged. The dgmo CLI also
  preserves the full legend by default; pass exportMode: true to
  renderForExport() for static-export semantics.

Breaking changes (Type API)

• LegendMode literal values changed from 'fixed' | 'inline' to
  'preview' | 'export'. Re-exported via @diagrammo/dgmo/advanced.
  Audited workspace-internal consumers (obsidian-dgmo,
  diagrammo_app_site, remark-dgmo, astro-dgmo,
  docusaurus-plugin-dgmo, fumadocs-dgmo) — zero direct usages. External
  npm consumers that read LegendMode literal values directly will need
  to update.
• matchColorParens() and inferArrowColor() removed from
  @diagrammo/dgmo/advanced. External consumers that imported them must
  drop the calls — edges no longer carry color, and (color) parens are
  no longer recognized.
• GraphEdge.color, SitemapEdge.color, LayoutEdge.color (sitemap +
  graph) fields removed from public types.