fix(templates): point constitution sync checklist at installed command files (#3418)

* fix(templates): point constitution sync checklist at installed command files

The consistency-propagation checklist told the agent to read
.specify/templates/commands/*.md, but specify init never creates that
directory — command templates are rendered straight into the
agent-specific directory (.github/prompts/, .claude/commands/, ...).
The checklist step could therefore never run against real files.

Point it at the installed speckit.* command files for the active agent
instead.

Fixes #660

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(templates): cover hyphenated and skills-mode command filenames

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(templates): use actual integration output directories in examples

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* docs(templates): cover skills-based command layouts in sync checklist

Copilot skills mode installs speckit-<name>/SKILL.md under .github/skills/,
not .github/agents/. Mention both directories and the SKILL.md layout.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* docs(templates): restore hyphenated speckit-* naming in sync checklist

The previous commit dropped the speckit-* flat-file variant used by
Cline and others while adding the SKILL.md layout. Name all three:
speckit.*, speckit-*, and speckit-<name>/SKILL.md.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* docs: clarify agent-specific reference phrasing in constitution template

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: marcelsafin

templates/commands/constitution.md

@@ -81,7 +81,7 @@ Follow this execution flow:
    - Read `.specify/templates/plan-template.md` and ensure any "Constitution Check" or rules align with updated principles.
    - Read `.specify/templates/spec-template.md` for scope/requirements alignment—update if constitution adds/removes mandatory sections or constraints.
    - Read `.specify/templates/tasks-template.md` and ensure task categorization reflects new or removed principle-driven task types (e.g., observability, versioning, testing discipline).
-   - Read each command file in `.specify/templates/commands/*.md` (including this one) to verify no outdated references (agent-specific names like CLAUDE only) remain when generic guidance is required.
+   - Read each installed Spec Kit command file for your agent (including this one) — named `speckit.*` or `speckit-*` (dot or hyphen depending on the agent), or laid out as `speckit-<name>/SKILL.md` for skills-based integrations, e.g. in `.github/agents/`, `.github/skills/`, `.claude/skills/`, or your agent's equivalent commands directory — to verify no outdated references (CLAUDE-only or other agent-specific names) remain when generic guidance is required.
    - Read any runtime guidance docs (e.g., `README.md`, `docs/quickstart.md`, or agent-specific guidance files if present). Update references to principles changed.
 
 5. Produce a Sync Impact Report (prepend as an HTML comment at top of the constitution file after update):