feat: implement preset wrap strategy

[kennedy-whytech]

Description

Implements strategy: wrap for preset commands, which was listed as a roadmap
item in presets/README.md. When a preset command sets strategy: wrap, the
{CORE_TEMPLATE} placeholder in its body is substituted with the body of the
installed core speckit command template at install time.

This lets preset authors add pre/post logic around core commands without
copy-pasting the entire command body — useful for extending frequently-updated
templates like /speckit.specify or /speckit.tasks. Personally, I find it neccessary.

Changes

• src/specify_cli/presets.py — adds _substitute_core_template() helper;
  wires substitution into _register_skills (skills-backed agents like Claude)
• src/specify_cli/agents.py — wires substitution into register_commands
  (all other agent types)
• presets/self-test/ — adds a speckit.wrap-test command for E2E coverage
• presets/README.md — marks wrap as implemented for command/template types

Test results

184 tests pass (tests/test_presets.py), including a new TestWrapStrategy
class with unit tests for the helper and an end-to-end install test.

Manual test results

Agent: Claude Code | OS/Shell: macOS/zsh

Command tested	Notes
specify preset install with strategy: wrap command	{CORE_TEMPLATE} correctly substituted in written skill/command file

AI assistance disclosure

This PR was implemented with AI assistance (Claude Code) for code generation,
test writing, and commit messages. All changes were reviewed and verified
manually.

Testing

• Tested locally with uv run specify --help
• Ran existing tests with uv sync && uv run pytest
• Tested with a sample project (if applicable)

AI Disclosure

• I did not use AI assistance for this contribution
• I did use AI assistance (describe below)

[Copilot]

Pull request overview

Adds support for strategy: wrap on preset-provided commands, enabling preset authors to inject pre/post content around an existing “core” command body via a {CORE_TEMPLATE} placeholder during command/skill registration.

Changes:

• Introduces _substitute_core_template() and applies it during preset skill registration (_register_skills) and generic agent command registration (CommandRegistrar.register_commands).
• Extends the self-test preset with a new speckit.wrap-test command and updates docs to mark wrap as implemented for commands.
• Adds unit + E2E-style tests covering placeholder substitution and install behavior.

Show a summary per file

File	Description
tests/test_presets.py	Updates self-test manifest expectations; adds new TestWrapStrategy coverage.
src/specify_cli/presets.py	Adds _substitute_core_template() and wires it into preset skill generation.
src/specify_cli/agents.py	Wires wrap substitution into agent command registration.
presets/self-test/preset.yml	Adds a new wrap-strategy command entry to the self-test preset.
presets/self-test/commands/speckit.wrap-test.md	Adds a wrap command template using {CORE_TEMPLATE}.
presets/README.md	Updates roadmap/docs to reflect wrap implemented for commands/artifacts.

Copilot's findings

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• Files reviewed: 6/6 changed files
• Comments generated: 1

[Copilot]

_substitute_core_template() doesn’t use project_root to locate the project’s installed core command templates under .specify/templates/commands (it only checks the packaged core_pack/commands or repo templates/commands). This breaks the stated behavior of wrapping the installed core template and will fail for commands that exist only in the project (e.g. wrap-test in the new tests). Consider resolving the core template path from project_root/.specify/templates/commands/<short_name>.md first (falling back to core_pack/repo only if missing), or otherwise remove/rename the project_root parameter/docstring to match actual behavior.

Suggested change

	from specify_cli import _locate_core_pack
	core_pack = _locate_core_pack()
	if core_pack is not None:
	core_file = core_pack / "commands" / f"{short_name}.md"
	else:
	# Source / editable install: look relative to the package root
	repo_root = Path(__file__).parent.parent.parent
	core_file = repo_root / "templates" / "commands" / f"{short_name}.md"
	core_file = project_root / ".specify" / "templates" / "commands" / f"{short_name}.md"
	if not core_file.exists():
	from specify_cli import _locate_core_pack
	core_pack = _locate_core_pack()
	if core_pack is not None:
	core_file = core_pack / "commands" / f"{short_name}.md"
	else:
	# Source / editable install: look relative to the package root
	repo_root = Path(__file__).parent.parent.parent
	core_file = repo_root / "templates" / "commands" / f"{short_name}.md"

[mnriem]

Please address Copilot feedback. If not applicable, please explain why