docs(copilot): correct a resume comment the rewind fix left inaccurate

The `unexamined` case claimed "everything read is emitted as text by the
caller". That was true when the resume was exactly the window edge, but the
straddling-opener rewind holds the last marker's worth of the window back so it
can be re-scanned rather than flattened — so the sentence contradicted the
paragraph directly beneath it. Nothing is lost either way; the caller emits up
to wherever this resumes.

Also drops two "Round-N class:" prefixes from test comments. They point at
review rounds of this PR, which mean nothing to a reader after it merges; the
sentences that follow already say what the bug was.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: j15z

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/special-tags/special-tags.test.ts

@@ -916,7 +916,7 @@ describe('parser properties', () => {
   })
 
   it('renders every valid tag as a card whatever surrounds it', () => {
-    // Round-3 class: a valid tag was flattened to text purely because of how much
+    // A valid tag was flattened to text purely because of how much
     // prose preceded it, which no fixed example set would have found.
     for (let seed = 1; seed <= 400; seed++) {
       const rng = makeRng(seed)
@@ -943,7 +943,7 @@ describe('parser properties', () => {
   })
 
   it('never un-renders a card or retracts text across streamed frames', () => {
-    // Round-5 class: content already on screen disappeared when a later close
+    // Content already on screen disappeared when a later close
     // arrived. Only visible across frames, never in an end-state assertion.
     //
     // Text may shrink slightly at a frame edge: a half-arrived opening marker is

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/special-tags/special-tags.tsx

@@ -937,9 +937,12 @@ function resumeForClass(cls: BodyClass, bodyStart: number, pastClose: number): n
       // Rescan the whole body: nothing was blanked, so no marker is hidden.
       return bodyStart
     case 'unexamined':
-      // Resume just short of the first character NOT read. Everything read is
-      // emitted as text by the caller, and this advances nearly a full window per
-      // step, so a long body still costs a bounded number of re-entries.
+      // Resume just short of the first character NOT read: the last marker's
+      // worth of the window is held back rather than emitted as text, so it is
+      // re-scanned on the next pass instead of being flattened. Nothing is lost
+      // — the caller emits up to wherever this resumes. It still advances nearly
+      // a full window per step, so a long body costs a bounded number of
+      // re-entries.
       //
       // The rewind is load-bearing: the window edge is an arbitrary cut, so an
       // opener can straddle it. Resuming exactly at the edge leaves that opener's