Feature: Plan CLI helper function branch coverage for legacy removal
  As a developer
  I want to cover remaining uncovered branches in plan.py helper functions
  So that coverage for plan.py improves after the legacy removal changes

  Background:
    Given the plan branch coverage helpers are initialized

  # ── _format_relative_time: naive datetime normalization (line 150) ────────

  Scenario: _format_relative_time normalizes naive datetime to UTC for 2h
    Given a plan-br naive datetime 2 hours in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should contain "2 hours"

  # ── _format_relative_time: future timestamp guard (line 156) ──────────────

  Scenario: _format_relative_time returns just now for future timestamp
    Given a plan-br naive datetime 10 minutes in the future
    When I call _format_relative_time on it
    Then the plan-br relative time should be "just now"

  # ── _format_relative_time: singular forms ─────────────────────────────────

  Scenario: _format_relative_time returns singular "1 minute ago"
    Given a plan-br naive datetime 1 minute in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "1 minute ago"

  Scenario: _format_relative_time returns singular "1 hour ago"
    Given a plan-br naive datetime 1 hour in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "1 hour ago"

  Scenario: _format_relative_time returns singular "1 day ago"
    Given a plan-br naive datetime 1 day in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "1 day ago"

  # ── _format_relative_time: plural forms ───────────────────────────────────

  Scenario: _format_relative_time returns plural "2 minutes ago"
    Given a plan-br naive datetime 2 minutes in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "2 minutes ago"

  Scenario: _format_relative_time returns plural "2 hours ago"
    Given a plan-br naive datetime 2 hours in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "2 hours ago"

  Scenario: _format_relative_time returns plural "2 days ago"
    Given a plan-br naive datetime 2 days in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "2 days ago"

  # ── _format_relative_time: seconds boundary ───────────────────────────────

  Scenario: _format_relative_time returns just now for 30 seconds ago
    Given a plan-br naive datetime 30 seconds in the past
    When I call _format_relative_time on it
    Then the plan-br relative time should be "just now"