[codex] Share target help fragments

[WilliamK112]

Summary

• add shared target-help display fragments next to the target parser constants
• reuse those fragments in install, compile, deps update, and update help text
• pin the relationship with a CLI consistency regression test

Context

Follow-up to #1821 and the review-panel observation that target help examples are maintained independently across commands. This keeps the visible target list and all expansion aligned with the canonical display order.

Testing

• .venv/bin/python -m pytest tests/unit/test_cli_consistency.py::test_target_help_uses_shared_display_fragments tests/unit/test_update_command.py::TestUpdateCommandLogic::test_dependency_update_help_lists_kiro_target_example tests/unit/core/test_target_detection.py::TestTargetParamType -q
• .venv/bin/python -m pytest tests/unit/test_cli_consistency.py tests/unit/commands/test_targets_command.py -q
• .venv/bin/ruff check src/apm_cli/core/target_detection.py src/apm_cli/commands/install.py src/apm_cli/commands/compile/cli.py src/apm_cli/commands/deps/cli.py src/apm_cli/commands/update.py tests/unit/test_cli_consistency.py
• .venv/bin/ruff format --check src/apm_cli/core/target_detection.py src/apm_cli/commands/install.py src/apm_cli/commands/compile/cli.py src/apm_cli/commands/deps/cli.py src/apm_cli/commands/update.py tests/unit/test_cli_consistency.py
• git diff --check