feat: add Deploy MCP App

[joehan]

Adds the Deploy MCP App UI. (Chained off #10262)

[gemini-code-assist]

Code Review

This pull request introduces a visual interface for Firebase deployment within the Model Context Protocol (MCP) framework, featuring a new web-based UI and status polling mechanism. It also includes a safety check for Firestore index deployment and updates utility functions to support structured content. The review feedback highlights several critical improvements for the UI logic, specifically regarding the inefficient and error-prone re-rendering of logs during polling. Additionally, multiple comments point out violations of the repository's style guide concerning the use of "any" types and the preference for centralized logging over "console.error".

[gemini-code-assist]

Clearing and re-rendering the entire log list on every poll interval has several issues:

1. Performance: DOM manipulation becomes increasingly expensive as the log history grows.
2. Correctness: The addLog function generates a timestamp using new Date(). Re-rendering all logs causes every entry to display the time of the latest poll rather than when the log was actually received.
3. Data Loss: Local logs added before polling starts (e.g., the 'Starting deployment' message at line 86) are lost when innerHTML is cleared.

Consider tracking the number of logs already displayed and only appending new ones.

[gemini-code-assist]

Using console.error for user-facing error reporting is discouraged by the repository style guide (line 29). In this UI context, consider using the addLog function to display the error to the user.

Suggested change

	} catch (err: any) {
	console.error("Failed to connect app:", err);
	} catch (err) {
	addLog("Failed to connect app: " + (err instanceof Error ? err.message : String(err)), "error");

References

1. Use the central logger; never use console.log() for user-facing output. ^(link)