Review corrections: DESIGN.md wording, doubled warning prefix, a weak test

[MJohnson459]

Corrections from review of the milestone and attention-price changes. Only items 3 and 4 change behaviour.

1. DESIGN.md §7, "No attention price": cut to the rule and a one-sentence reason. The per-action values, the removal date and the 47th/48th/75th ranks are gone; the CHANGELOG keeps them. voro next and the first ready queue row now name the same task, milestones aside, only under two stated conditions: the dispatch WIP cap is not reached (at the cap the queue drops dispatch rows while next ignores the gate), and a ready row makes the ten-row cut.
2. DESIGN.md §5: rewrapped the max_running/[costs] paragraph. "Left over from the attention price" now reads as a statement of the design.
3. voro.toml with a [costs] table: the CLI printed voro: warning: the [costs] table …. main.rs now prints the warning text as it is, so the line reads warning: the [costs] table …. The core string keeps its warning: prefix, so the TUI status line and the Config screen do not change. The new integration test crates/voro/tests/costs_table_warning.rs runs the binary with a scratch XDG_CONFIG_HOME and checks that exactly one line, with one prefix, mentions [costs]. With the old print the test fails.
4. r_and_capital_r_refine_a_proposed_milestone: the test context now sets up a stub agent with a plan verb. The test asserts that R queues a refine launch whose RefineLaunch.task_id is the milestone, and that the prompt file it writes contains the milestone guidance ("This task is a milestone").
5. dispatch.rs: the four milestone shapes now say the title "is a label cut to 16 characters" instead of "fills a 16-character column". I rewrapped them to the width of the surrounding lines. DESIGN.md §8 had the same wording and got the same fix. SKILL.md never said "column".
6. History phrasing in the milestone sections, rewritten: §8 "byte-for-byte what it was before milestones existed" → "carries no milestone text"; §9 "The cockpit gains a label" → "shows milestones as a label", and "reads as it did before milestones existed" → "reserves no width for one". In §6, "is refused too" became "is also refused", because the acceptance grep for "used to" matched "refused too".

Verification: cargo test --workspace passes (554 + 424 unit tests, 2 integration tests), cargo clippy --workspace --all-targets -- -D warnings is clean, and grep -n -E "2026-0|47th|used to" docs/DESIGN.md prints nothing.