fix(cliproxy): silence legacy-config skip in pool opt-in prompt

Legacy profiles.json-only installs get pool guidance exclusively from
ccs doctor (once-per-install semantics); printing a migrate notice on
every account add nagged with no dismissal available. Also document why
type === 'account' profiles are Claude by schema in the onboarding
counter, so the filter is not misread as over-counting.

src/cliproxy/routing/pool-onboarding-hint.ts

@@ -96,6 +96,11 @@ function isPoolEnabled(config?: UnifiedConfig): boolean {
  *
  * Uses ProfileRegistry so the count respects both legacy profiles.json and
  * unified config accounts - same source of truth as the rest of the codebase.
+ *
+ * type === 'account' implies Claude: per the profile-registry schema, every
+ * account profile is an isolated Claude instance (CLAUDE_CONFIG_DIR lane) with
+ * no CLI discriminator. Gemini/Codex multi-account lives in CLIProxy auth
+ * files, never in profiles.json, so this filter cannot over-count.
  */
 export function countNativeClaudeProfiles(): number {
   try {

src/cliproxy/routing/pool-opt-in-prompt.ts

@@ -149,13 +149,10 @@ export async function maybeOfferPoolRouting(
   // orphaning the user's config.json profiles.  Skip entirely before any prompt
   // or dismissal persistence.  Mirrors the guards in create-command.ts and
   // account-flow.ts and the hazard documented in pool-onboarding-hint.ts.
+  // Silent by design: legacy installs receive pool guidance exclusively from
+  // ccs doctor (pool-onboarding-hint site 1); printing here would nag on every
+  // account add with no dismissal available.
   if (!hasUnifiedConfig()) {
-    console.log(
-      info(
-        '[i] Multiple accounts detected, but pool routing needs the unified config. ' +
-          "Run 'ccs migrate' first, then 'ccs cliproxy pool --enable'."
-      )
-    );
     return { prompted: false, enabled: false, skipped: true, skipReason: 'legacy-config' };
   }