refactor(checkpoint): inline workflow into SKILL.md and add global step rules

Remove separate workflow.md — its content now lives directly in SKILL.md
with merged frontmatter. Replace scattered standing rules with a structured
Global Step Rules section (path:line format, front-load output, comm style).

src/bmm-skills/4-implementation/bmad-checkpoint-preview/SKILL.md

@@ -1,6 +1,28 @@
 ---
 name: bmad-checkpoint-preview
 description: 'Guided walkthrough of a change, from purpose and context into details. Use when the user says "walk me through this change", "human review", or "review walkthrough".'
+main_config: '{project-root}/_bmad/bmm/config.yaml'
 ---
 
-Follow the instructions in ./workflow.md.
+# Checkpoint Review Workflow
+
+**Goal:** Guide a human through reviewing a change — from purpose and context into details.
+
+You are assisting the user in reviewing a change.
+
+## Global Step Rules (apply to every step)
+
+- **Path:line format** — Every code reference must be clickable `path:line` (absolute or relative to repo root).
+- **Front-load then shut up** — Present the entire output for the current step in a single coherent message. Do not ask questions mid-step, do not drip-feed, do not pause between sections.
+- **Communication style** — Always output using the exact Agent communication style defined in SKILL.md and the loaded config.
+
+## INITIALIZATION
+
+Load and read full config from `{main_config}` and resolve:
+
+- `implementation_artifacts`
+- `communication_language`
+
+## FIRST STEP
+
+Read fully and follow `./step-01-orientation.md` to begin.

src/bmm-skills/4-implementation/bmad-checkpoint-preview/workflow.md

@@ -1,24 +0,0 @@
----
-main_config: '{project-root}/_bmad/bmm/config.yaml'
----
-
-# Checkpoint Review Workflow
-
-**Goal:** Guide a human through reviewing a change — from purpose and context into details.
-
-You are assisting the user in reviewing a change.
-
-**Standing rule:** Every code reference you produce must use clickable `path:line` format — absolute or relative to the current working directory (e.g., `src/auth/middleware.ts:42`).
-
-## INITIALIZATION
-
-Load and read full config from `{main_config}` and resolve:
-
-- `implementation_artifacts`
-- `communication_language`
-
-YOU MUST ALWAYS SPEAK OUTPUT in your Agent communication style with the config `{communication_language}`.
-
-## FIRST STEP
-
-Read fully and follow `./step-01-orientation.md` to begin.