feat(svg): let an SVG icon state the text it stands for

[DemchaAV]

Why

A colour emoji is drawn from SVG paths, so the page has no character where it sits: a line with :rocket: in it, copied out of a PDF into a messenger, arrives without the rocket. The renderer cannot put the emoji back, because it never sees it — RichText.emoji(":rocket:") resolves the shortcode to an SvgIcon and keeps only the drawing. The text has to travel with the icon first; the PDF backend writes it in a following PR.

What changed

• SvgIcon.text() / SvgIcon.withText(String) (@since 2.5.0) — the text an icon drawn inline stands for when the page is read as text. withText returns a copy sharing the layers and frame; null or blank clears it. A block icon (addSvgIcon, SvgIcon.node) does not carry it. The text lives on the icon rather than on the run, so a custom icon states it once (SvgIcon.read(path).withText("✓")) and every svgIcon(icon, size) / inlineSvgIcon(icon, size) overload carries it with no new overloads — a String overload next to svgIcon(icon, size, alignment) would also have made svgIcon(icon, size, null) ambiguous.
• EmojiLibrary sets the text on every icon it resolves, spelled from the glyph key.
• EmojiSequences (package-private) restores what the key drops. Keys follow Noto's file names, which omit U+FE0F; without it a text-default emoji such as U+2764 can paste as a plain black symbol. The text is the fully-qualified form of UTS docs: reorganise into categorised folders + real docs index + link audit #51: U+FE0F after every character whose default presentation is text, unless a skin-tone modifier or a selector already follows. The 219 such characters are a sorted table generated from Character.isEmoji / isEmojiPresentation; Java 17 has neither, so the table cannot be computed at runtime.
• No emoji-set release needed: the published graph-compose-emoji 1.0.0, which the core tests resolve against, yields the same text.

Verification

• Full CI reactor gate (./mvnw -B -ntp clean verify -pl <the 10 CI modules> -am) → BUILD SUCCESS, 13 modules, 3246 tests, 0 failures.
• ./mvnw -P japicmp verify -pl :graph-compose-core → BUILD SUCCESS (additions only). javadoc:javadoc -pl :graph-compose-core → BUILD SUCCESS, 0 warnings.
• EmojiSequencesTest (9) pins the spelling: rocket plain, heart and © gain FE0F, ZWJ sequences (woman technologist, man health worker, eye in speech bubble), a skin-tone modifier suppresses the selector, a keycap base is qualified before U+20E3, an existing FE0F/FE0E is not doubled, malformed keys give null. It also compares the table with the running JDK's Unicode data on JDK 21+ — ran on JDK 24 (219 codepoints, identical on JDK 23); CI's 21 and 25 legs run it too.
• EmojiLibraryTest +2: :rocket:, :heart:, :woman_technologist: carry their text; a glyph named by anything but codepoints resolves and draws without text.
• SvgIconTextTest (4): parsed icons state no text, withText copies and leaves the original unchanged, null/blank clear, text is kept verbatim.
• Knowledge pack regenerated (authoring: +text(), +withText(String)).

Notes

• @since 2.5.0 — this adds public API while the in-progress CHANGELOG heading reads v2.4.1 — Planned; the next cut is a minor under semver.

Lane: canonical (document.svg, document.emoji) — no render change in this PR.

Merge order: first; the PDF text layer (stacked PR) builds on it.