tui: Ink's counter, borders, use-focus and static side by side, a text field, and the README's front

[shreeve]

PLAN step 6, the examples half.

Four of Ink's examples, ported. examples/ink/{counter,borders,use-focus,static}.rip, each the same program as Ink's <name>.tsx beside it (copied unmodified; NOTICE names them). Each port was run against Ink 7.1.1's own frames for the same program: every frame is identical, so no stated difference was needed. Lines, non-blank and non-comment, counted by test/lines.rip and asserted by test/examples.rip:

Example	Ink	Rip TUI
counter	15	6
borders	34	21
use-focus	26	19
static	45	14

Two behaviors stated in the file headers: borders says flexDirection: 'row' on its two rows since a Box here is a column; static calls quit() at its tenth test, since Ink's process ends when its last timer drains while run holds stdin.

A text field. examples/input.rip, 40 code lines: typing inserts one code point at the cursor, arrows, Home and End move it, Backspace and Delete take one grapheme cluster, a paste inserts whole, Enter prints the value above the frame and clears, Escape clears; the cursor is placed by cursor: with the column measured over the clusters before it. This is the text-input example PLAN step 4's exit named.

Every example runs headless through mount in test/examples.rip (7 tests): the timer counter driven by view.tick, focus by Tab, the static scrollback and live frame, the field's frame and view.cursor after each key. Each also runs from a terminal (rip examples/ink/counter.rip) through the run X if import.meta.main guard.

README. The top reads, in order: the thesis in plain words; a quick start on the keyboard counter with the two commands; the feature matrix reconciled with what is built (every row of "Matches Ink" and "Beyond Ink" is built and under test; TODO lists the open work within them); the four examples side by side with their lines; the examples table. A <!-- bench --> marker holds the place for the published numbers, which the bench half writes.

One gap found and listed in TODO, not fixed: a stdout.columns of 0 draws empty frames where undefined reads as 80.

Suites unchanged plus examples 7; root style gate passes.