Reduce internal-only labeling noise in source comments (#355)

This pass rewrites comment-only ANT-ONLY markers to neutral internal-only
language across the source tree without changing runtime strings, flags,
commands, or protocol identifiers. The goal is to lower obvious internal
prose leakage while keeping the diff mechanically safe and easy to review.

Constraint: Phase B is limited to comments/prose only; runtime strings and user-facing labels remain deferred
Rejected: Broad search-and-replace across strings and command descriptions | too risky for a prose-only pass
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Remaining ANT-ONLY hits are mostly runtime/user-facing strings and should be handled separately from comment cleanup
Tested: bun run build
Tested: bun run smoke
Tested: bun run verify:privacy
Tested: bun run test:provider
Tested: bun run test:provider-recommendation
Not-tested: Full repo typecheck (upstream baseline remains noisy)

Co-authored-by: anandh8x <test@example.com>

src/services/SessionMemory/sessionMemory.ts

@@ -282,7 +282,7 @@ const extractSessionMemory = sequential(async function (
 
   // Check gate lazily when hook runs (cached, non-blocking)
   if (!isSessionMemoryGateEnabled()) {
-    // Log gate failure once per session (ant-only)
+    // Log gate failure once per session (internal-only)
     if (process.env.USER_TYPE === 'ant' && !hasLoggedGateFailure) {
       hasLoggedGateFailure = true
       logEvent('tengu_session_memory_gate_disabled', {})
@@ -359,7 +359,7 @@ export function initSessionMemory(): void {
   // Session memory is used for compaction, so respect auto-compact settings
   const autoCompactEnabled = isAutoCompactEnabled()
 
-  // Log initialization state (ant-only to avoid noise in external logs)
+  // Log initialization state (internal-only to avoid noise in external logs)
   if (process.env.USER_TYPE === 'ant') {
     logEvent('tengu_session_memory_init', {
       auto_compact_enabled: autoCompactEnabled,