[thrawn01]

Purpose

Workers were told they could tag a slow test tests_slow without asking. In the user's Bazel mono-repo, changing a test's tag made Bazel rebuild and rerun the whole suite, so one tag edit cost a full run. A rule that fits dispatch's repo was applied to codebases it doesn't fit.

After this change grep -r tests_slow skills/ prints nothing. A test still over 1 second now follows the codebase's own way of handling slow tests, and a worker is told not to invent one. The 1 second per test and 5 minutes per suite budget is unchanged.

Implementation

• skills/build/SKILL.md drops the standing exception that let a worker tag a test without quoting the user.
• skills/principle-fast-tests/SKILL.md replaces the tag paragraph with "follow the codebase's own way; if it has none, leave the test and report its time and what you tried". It also loses "tagging" from the description and -tags tests_slow from the test-report line.
• skills/surface-testing/SKILL.md and skills/repo-targets/SKILL.md lose the tag pointers, the test-slow row and the "add targets before tagging" sentence.
• Calls on the ticket's open questions (also commented on ENG-589): generic wording instead of dropping the guidance, and dispatch's own tests_slow tag stays. CLAUDE.md, README.md, the Makefile, CI, cmd/slowtests, internal/slowtests and the tagged tests are untouched, so those still describe the tag for this repo.

Verification: ran grep -r tests_slow skills/ (empty). No evals, per the ticket. A fresh sub-agent loaded skill-creator and reviewed the changed skills without test prompts. I took its wording fix (report "what you tried", not "why it can't be faster") and left its suggestions to trim unrelated existing lines. No Go code changed, so I ran no tests.

Fixes ENG-589