fix: replace hardcoded /Users/jesse with generic placeholders (#858)

[arittr]

What problem are you trying to solve?

Several files contained hardcoded /Users/jesse paths (#858). These paths break for any user on a different system and leak personal directory structure into the codebase.

What does this PR change?

Replaces all hardcoded /Users/jesse paths with generic placeholders (e.g. ~/project, <project-root>) in docs/testing.md, skills/systematic-debugging/CREATION-LOG.md, and skills/systematic-debugging/root-cause-tracing.md.

Is this change appropriate for the core library?

Yes — hardcoded user paths in shared docs/skills are a bug that affects all users.

What alternatives did you consider?

1. Using $HOME environment variable references — less readable in documentation context.
2. Only fixing new occurrences going forward — leaves existing broken examples for users who copy-paste.

Does this PR contain multiple unrelated changes?

No. All changes address the same issue: replacing hardcoded /Users/jesse paths with generic placeholders.

Existing PRs

• I have reviewed all open AND closed PRs for duplicates or prior art
• Related PRs: replace hardcoded /Users/jesse sample paths with generic placeholders #858 (the issue this addresses)

Environment tested

Harness (e.g. Claude Code, Cursor)	Harness version	Model	Model version/ID
Claude Code	latest	Claude Opus 4.6	claude-opus-4-6

Evaluation

• Grep confirmed no remaining /Users/jesse references after the change
• Documentation examples render correctly with generic placeholders

Rigor

• If this is a skills change: I used superpowers:writing-skills and
  completed adversarial pressure testing (paste results below)
• This change was tested adversarially, not just on the happy path
• I did not modify carefully-tuned content (Red Flags table,
  rationalizations, "human partner" language) without extensive evals
  showing the change is an improvement

Human review

• A human has reviewed the COMPLETE proposed diff before submission

[arittr]

This change is part of the following stack:

• adjust worktree handling and defer to harness tools when avail (PRI-974) #1121
  • fix: replace hardcoded /Users/jesse with generic placeholders (#858) #1122 ◀
    • feat: add multi-repo worktree guidance (#710) #1123
      • enhance worktree consent during implementation (PRI-974) #1124
        • fix: close sibling-worktree loophole in already-inside path #1153

_{Change managed by git-spice.}