fix(sf): replace developer-machine paths with portable placeholders

Three bundled files referenced /home/mhugo/code/singularity-forge in
example commands and prompt templates. They ship to every SF install,
where /home/mhugo/code/ doesn't exist:

- workflow-templates/full-project.md: "defined in SF-WORKFLOW.md" was
  ambiguous (LLM resolves relative to cwd). Now points at the canonical
  ~/.sf/agent/SF-WORKFLOW.md install path (per loader.ts:236).

- skills/context-doctor/SKILL.md: Step 6 commit example used
  "cd /home/mhugo/code/singularity-forge". Generic "<project-root>"
  works for any user.

- skills/dispatching-subagents/SKILL.md: subagent task-prompt template
  hardcoded "Repo: /home/mhugo/code/singularity-forge" in the CONTEXT
  section. Same fix.

The acquiring-skills skill has more dev-specific content (mikki-bunker
host, /home/mhugo/code/, dev-tree copy paths) that's clearly a personal
workflow shipping in the bundled tree — left untouched here, needs a
real triage decision (delete from bundle vs generalize).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/resources/extensions/sf/skills/context-doctor/SKILL.md

@@ -93,7 +93,7 @@ After repair:
 ### Step 6 — Commit
 
 ```bash
-cd /home/mhugo/code/singularity-forge
+cd <project-root>
 git status --short
 git diff
 git add .sf/<files-changed>                   # only what you actually changed

src/resources/extensions/sf/skills/dispatching-subagents/SKILL.md

@@ -240,7 +240,7 @@ For non-milestone changes, use [`requesting-code-review`](../requesting-code-rev
 TASK: <one-sentence summary>
 
 CONTEXT:
-- Repo: /home/mhugo/code/singularity-forge
+- Repo: <project-root>
 - Key files: <list specific paths and what they contain>
 - Architecture: <brief relevant context — phase machine, harness boundary, etc.>
 - Doctrine: AGENTS.md and docs/SPEC_FIRST_TDD.md

src/resources/extensions/sf/workflow-templates/full-project.md

@@ -35,7 +35,7 @@ it should route to the standard SF workflow:
 2. If `.sf/` exists but no milestones: Start the discuss phase via `/sf discuss`
 3. If milestones exist: Resume via `/sf autonomous` or `/sf next`
 
-The full SF workflow protocol is defined in `SF-WORKFLOW.md` and handles all
+The full SF workflow protocol is defined in `~/.sf/agent/SF-WORKFLOW.md` and handles all
 phases, state tracking, and agent orchestration.
 
 </process>