fix: stop dimming setup card bodies

Clack's `p.note` defaults to `format: e => styleText("dim", e)`, which
fades note bodies regardless of the project's stated readability stance
(see comment on `dimWrap` in setup/lib/theme.ts: "prose renders at the
terminal's regular weight"). The dim styling makes body copy hard to
read on dark terminals and visibly washes out brand-colored segments
embedded in cards (e.g. the chip + bold heading rows).

Add a `note()` helper in setup/lib/theme.ts that wraps `p.note` with a
pass-through formatter, and route every setup-flow `p.note` call site
through it: setup/auto.ts, every setup/channels/*.ts adapter, and the
two setup/lib/claude-* helpers.

Pre-styled segments (brandBold, brandChip, formatPairingCard,
formatCodeCard) now render at full strength instead of being faded
alongside surrounding prose.

setup/channels/slack.ts

@@ -28,7 +28,7 @@ import * as setupLog from '../logs.js';
 import { confirmThenOpen } from '../lib/browser.js';
 import { askOperatorRole } from '../lib/role-prompt.js';
 import { ensureAnswer, fail, runQuietChild } from '../lib/runner.js';
-import { wrapForGutter } from '../lib/theme.js';
+import { note, wrapForGutter } from '../lib/theme.js';
 
 const SLACK_API = 'https://slack.com/api';
 const SLACK_APPS_URL = 'https://api.slack.com/apps';
@@ -121,7 +121,7 @@ export async function runSlackChannel(displayName: string): Promise<void> {
 }
 
 async function walkThroughAppCreation(): Promise<void> {
-  p.note(
+  note(
     [
       "You'll create a Slack app that the assistant talks through.",
       "Free and stays inside the workspaces you pick.",
@@ -262,7 +262,7 @@ async function validateSlackToken(token: string): Promise<WorkspaceInfo> {
 }
 
 async function collectSlackUserId(): Promise<string> {
-  p.note(
+  note(
     [
       "To get your Slack member ID:",
       '',
@@ -367,7 +367,7 @@ async function resolveAgentName(): Promise<string> {
 }
 
 function showPostInstallChecklist(info: WorkspaceInfo): void {
-  p.note(
+  note(
     wrapForGutter(
       [
         `Your agent is wired to Slack and a welcome DM is on its way.`,