Ellipsis animation causes confirmation dialog bob

### Reproduction steps 1. Start Zed and open the Agent Panel (or trigger any tool call that shows the "Awaiting Confirmation…" dialog). 2. Resize the window (or narrow the panel) so the confirmation text sits just shy of its wrap threshold — roughly where one more character would push it onto a second line. 3. Watch the dialog as the ellipsis animates through `.`, `..`, `...`. ### Current vs. Expected behavior **Current:** the animated ellipsis cycles the *number of dots rendered*. When the 3-dot state is one character past the wrap point, the text wraps onto a second line, the dialog grows a line taller, then shrinks back as the dots cycle back down. The confirmation box visibly bobs up and down in time with the animation. In addition to being visually distracting, it also means using the mouse on the dialog requires timing, because the delta in button position is wider than the button itself. **Expected:** the dialog's size stays fixed regardless of the animated dot count — the ellipsis animates without reflowing the layout. ### Zed version and system specs Zed: v1.15.0+stable.339.e17dc4f9d50db73a458b64dcce50ecd4878b98a3 (Zed) OS: macOS 26.5.2 Memory: 8 GiB Architecture: aarch64 ### Attach Zed log file <details><summary>Zed.log</summary> <!-- Paste your log inside the code block. --> ```log ``` </details> ### Relevant Zed settings <details><summary>settings.json</summary> <!-- Paste your settings inside the code block. --> ```json ``` </details> ### Relevant Keymap <details><summary>keymap.json</summary> <!-- Paste your keymap file inside the code block. --> ```json ``` </details> ### (for AI issues) Model provider details _No response_ ### If you are using WSL on Windows, what flavor of Linux are you using? _No response_