[FEATURE] Inline quote-replies send immediately instead of accumulating

Preflight Checklist

• I have searched existing requests and this feature hasn't been requested yet
• This is a single feature request (not multiple features)

Problem Statement

The new quote-reply box (select text in a response → "Responder a Claude")
sends each comment as a separate message, triggering a full assistant turn
per comment. Leaving six notes while reading a long response costs six
turns and six responses.
Artifact comments already work the way I want: they accumulate and are read
in a batch. The same model would fit here — collect quote-replies in a
pending queue, send them together when I hit submit on the main composer.
Right now the feature is unusable for its most natural use case: annotating
a long response while reading it.

Proposed Solution

Title: Inline quote-replies should accumulate, not send one turn per comment

## Current behaviour
Selecting text in a response opens a quote-reply box. Pressing the send
arrow submits that comment immediately as its own message, which triggers a
full assistant turn. Annotating a long response with six notes costs six
turns, six responses and six times the quota.

Why this is a problem

The natural use case for inline comments is reading a long response and
reacting as you go. That is exactly the case the current design punishes.
Users fall back to the main composer and quote fragments by hand, which
loses the anchoring the feature was built to provide.

Proposed solution

Artifact comments already solve this: notes accumulate on the page and the
assistant reads them in one batch. Apply the same model here.

1. Make the primary action in the quote box "Add comment", not "Send". The
   comment is stored, not submitted.
2. Show each stored comment as a small marker anchored to its quoted
   fragment, so the user sees what they have already flagged while they
   keep reading.
3. Show a pending count on the main composer ("3 comments"). Pressing send
   there ships all of them in one message, each with its quoted fragment,
   in one assistant turn.
4. Let the user edit or delete a pending comment before sending.
5. Keep immediate send available as a secondary action — a modifier
   shortcut, or a small "send now" next to "Add comment" — for the one-off
   correction where the user does want an answer straight away.

Why this shape

It does not remove anything that works today: point 5 preserves the current
behaviour for the case it suits. It adds the batching for the case it does
not. And it reuses a mental model users already have from artifact
comments, so there is nothing new to learn.

Alternative Solutions

No response

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

No response

Additional Context

No response

Start by locating the interactive-mode quote-reply box and the existing artifact-comment flow described in the issue. Compare how each handles pending comments, then define the batching behavior, pending count, editing and deletion, immediate-send fallback, and one-turn submission as done criteria.