Make UI submit message prior to click even more insistent

[mattdholloway]

Summary

The changes clarify that the operations are not yet completed and emphasize that users must explicitly submit the form to finalize the action. This helps prevent confusion and ensures users do not mistakenly believe an issue or PR has been created or updated before submission.

Why

Fixes #

What changed

Clarification of confirmation requirements in UI flows:

• Updated the message shown when preparing to update an issue to stress that the issue has not been updated yet and to instruct assistants not to tell the user it was updated. The user must click Submit to confirm the operation (pkg/github/issues.go).
• Updated the message shown when preparing to create an issue to emphasize that the issue has not been created yet and to instruct assistants not to tell the user it was created. The user must click Submit to confirm the operation (pkg/github/issues.go).
• Updated the message shown when preparing to create a pull request to clarify that the PR has not been created yet and to instruct assistants not to tell the user it was created. The user must click Submit to confirm the operation (pkg/github/pullrequests.go).

MCP impact

• No tool or API changes
• Tool schema or behavior changed
• New tool added

Prompts tested (tool changes only)

Security / limits

• No security or limits impact
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Note: if you're renaming tools, you must add the tool aliases. For more information on how to do so, please refer to the official docs.

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed
• Updated (README / docs / examples)

[Copilot]

Pull request overview

This PR improves the clarity of UI submission messages to prevent LLMs from prematurely telling users that actions (creating/updating issues or PRs) have been completed when the user still needs to click Submit in the interactive form.

Changes:

• Updates UI gate messages to be more explicit and insistent
• Adds "IMPORTANT:" prefix and explicit "Do NOT tell the user" instructions
• Changes from generic "confirm this operation" to specific "click Submit in the form to [action] it"

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pkg/github/pullrequests.go	Updated create_pull_request UI gate message to be more explicit about PR not being created yet
pkg/github/issues.go	Updated issue_write UI gate messages for both create and update methods with clearer warnings

[tommaso-moro]

Haven't tested effectiveness but LGTM!