fix(orphan): prompt for confirmation when orphaning multiple branches (#733)

[mvanhorn]

Summary

av orphan now prompts for confirmation when it would orphan more than one branch, mirroring the trunk-context prompt pattern from av sync. A --yes / -y flag skips the prompt for scripted use.

Why this matters

From #733:

Running av orphan from the trunk branch (e.g. master) drops every av-managed branch in the repo with no confirmation. First-time users have no way to predict this from the command name or current help text, and recovery means re-adopting each branch one-by-one.

av sync already has the right pattern at cmd/av/sync.go:169-183, where the trunk-from-trunk case prompts "You are on the trunk, do you want to sync all stacks?" This patch mirrors that for multi-branch / trunk-context orphan operations.

Changes

• cmd/av/orphan.go: predicate + prompt + --yes flag, listing branches that will be orphaned
• cmd/av/orphan_test.go: new unit tests for prompt-denied / prompt-accepted / single-branch / --yes paths
• e2e_tests/orphan_test.go: updated to thread through the new prompt

Single-branch orphans from a feature branch are unchanged (no prompt). Pattern matches cmd/av/sync.go:169-183.

Fixes #733

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[aviator-app]

🔃 FlexReview Status

Common Owner: aviator-co/engineering (expert-load-balance assignment)
Owner and Assignment:

• 🔒 aviator-co/engineering (expert-load-balance assignment)
  • Slack: #av-slack-testing
  • Assigned: jainankit
  Owned Files

  • 🔒 e2e_tests/orphan_test.go
  • 🔒 cmd/av/orphan.go
  • 🔒 cmd/av/orphan_test.go

Review SLO: 7 business hours if PR size is <= 200 LOC for the first response.

[gemini-code-assist]

Code Review

This pull request introduces an interactive confirmation prompt when orphaning multiple branches using the av orphan command, along with a --yes flag to bypass the prompt. The core logic has been refactored into collectBranchesToOrphan and orphanBranches functions, and a new test case verifies that denying the prompt prevents the orphaning process. A typo was identified in the success message where 'branched' should be 'branches'.

[gemini-code-assist]

There is a typo in the output message: "branched" should be "branches".

Suggested change

	"These branched are orphaned: %s\n",
	"These branches are orphaned: %s\n",