Feat: Quick prompts

[tninja]

We might want to send out same prompt every couple of days or weeks. Eg. Summarise the recent AI coding related news. But we might not want to manually type or find the prompt. This feature is to make this thing easier.

Also do couple of code refactoring / improvement.

[Copilot]

Pull request overview

Adds a “quick prompts” shortcut for sending frequently reused prompts to the active AI session, while refactoring shared path/context helpers into a new utility module and tightening some backend-infra behaviors (terminal dispatch + session naming).

Changes:

• Introduce ai-code-quick-prompts + ai-code-send-quick-prompt and wire it into the transient menu.
• Refactor shared helpers (git root, project root, clipboard/window context, repo context formatting) into new ai-code-utils.el and update call sites.
• Improve backend infra: generic terminal operation dispatch, working-directory resolution via shared helper, and default instance-name preferring current git branch.

Reviewed changes

Copilot reviewed 22 out of 22 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
ai-code.el	Adds quick prompts customization/command; refactors checkpoint/debug prompt sending to reuse confirm/send helper; updates menu.
ai-code-utils.el	New shared utilities module (git/project roots, clipboard + context files, repo context formatting, task files dir).
ai-code-input.el	Requires new utils module and introduces ai-code--confirm-and-send helper for “edit then send” flows.
ai-code-prompt-mode.el	Switches to utils-provided helpers/constants; removes duplicated task-dir helpers.
ai-code-file.el	Uses shared helpers and ai-code--confirm-and-send for lint/build/test prompt flows; removes duplicated repo-context formatting.
ai-code-discussion.el	Replaces repeated read/edit/send patterns with ai-code--confirm-and-send; updates declarations to utils.
ai-code-github.el	Uses ai-code--confirm-and-send for review/PR prompt editing flow.
ai-code-backends-infra.el	Adds terminal operation dispatcher, uses shared session-root logic, and prefers branch name for default instance names.
ai-code-backends.el	Updates ai-code--git-root declaration to point at utils module.
ai-code-change.el	Updates clipboard/git-root/repo-context declarations to utils module.
ai-code-agile.el	Updates context-files/git-root declarations to utils module.
ai-code-behaviors.el	Updates clipboard/git-root declarations to utils module.
ai-code-gptel-agent.el	Updates git-root declaration to utils module.
ai-code-git.el	Updates ensure-files-directory/git-root declarations to utils module.
ai-code-harness.el	Updates ensure-files-directory/git-root declarations to utils module.
test/test_00-bootstrap.el	Makes packaged-library selection robust by filtering to directories.
test/test_ai-code.el	Updates checkpoint test to assert prompt insertion (vs direct CLI send/switch).
test/test_ai-code-utils.el	New test coverage for extracted utils helpers.
test/test_ai-code-file.el	Updates tests to stub ai-code-plain-read-string; adds session-project-root tests.
test/test_ai-code-prompt-mode.el	Adjusts note-search tests to assert inserted prompt; normalizes temp external dir via truename.
test/test_ai-code-onboarding.el	Makes packaged-transient selection robust by filtering to directories.
test/test_ai-code-backends-infra.el	Adds coverage for new default instance naming, session working dir delegation, and terminal dispatch routing.