ui(flows): consistent success headlines and file lists in init/install/setup/phase/docs

[codeaholicguy]

Scope

Mutating/flow commands: init, install, setup, phase, docs init-feature. They mostly use ui.* correctly, but have drift in result rendering.

Evidence

init completion:

AI DevKit project initialized successfully!   ← plain ui.text, no ✔/color
Next steps:
  • Review and customize templates in docs/ai/
  ...
  • Run `ai-devkit init` again to add more environments

docs init-feature:

✔ Created 3 feature doc(s) for my-feature.
docs/ai/requirements/2026-09-22-feature-my-feature.md
docs/ai/design/2026-09-22-feature-my-feature.md

setup: ui.summary (Setup Summary) + ui.table + Host Prerequisites + Next steps sections.

Problems

1. init's final success line is plain text (ui.text("AI DevKit project initialized successfully!")) while phase, docs, and skill add's headline use ui.success — the biggest moment in the flow has the weakest styling. (Compounded by ui.success calls mid-flow like Created configuration file, so the ending is quieter than the steps.)
2. docs init-feature file list is unstyled: plain relative paths, no indent, no dim, no -> prefix — reads as accidental output next to the ✔ line above it.
3. Naive pluralization: 3 feature doc(s).
4. setup mixes three section styles (ui.summary block, ui.table, bold-ish plain ui.text headers Host Prerequisites / Next steps) with inconsistent indenting between them.
5. init next-steps bullets use • with trailing \n embedded in the last ui.text string ("...environments\n") — manual spacing smuggled into content instead of a ui.breakline().
6. No --dry-run-style preview anywhere: flows print what they did, not what they will do; not required now, but result rendering should at least be consistent so a future preview can mirror it.

Expectation

• Every flow ends with a ui.success headline (✔ AI DevKit project initialized), steps above it dim/ℹ.
• File lists as indented dim lines with a consistent prefix ( → docs/ai/...), matching whatever per-item convention skill adopts.
• One section-header style for setup (bold ui.text + blank line), applied to all its sections.
• Shared pluralization (3 feature docs).
• No embedded \n in message strings; spacing via ui.breakline().

Files: packages/cli/src/commands/init.ts (~L236–300), packages/cli/src/commands/docs.ts (~L67–86), packages/cli/src/commands/setup.ts (~L38–68), packages/cli/src/commands/phase.ts (~L69–70)