docs(tools): describe MIT-default license boundary

[zoeyrose]

Summary

• describe atrinik/tools as MIT by default with a GPL-2.0-or-later map-checker-qt/ exception
• preserve the historical tools tag/release license boundary in organization-profile wording
• require the mixed-license wording in governance validation and its mutation tests

Supports atrinik/tools#22. This wording must deploy only with the owning tools transition.

Coordinates

• Base: main at 082bf91c7d2c82bfb353e9d5feb90ca12a2c1383
• Head: docs/tools-mit-default at 80124a192c5f879745f26e59db753470d304d03b
• Worktree: /workspaces/atrinik/workspace/worktrees/github-settings/issue-22-tools-mit-default
• Commits: d407a79, 4154969, 80124a1 fix(tools): bind checker license exception

Validation

• bin/validate — passed
• bash -n bin/validate tests/validate-community-health.sh — passed
• shellcheck bin/validate tests/validate-community-health.sh — passed
• actionlint — passed
• bin/publish — plan completed; reported broad pre-existing desired/live drift, no apply performed
• git diff --check — passed

Verification

Runtime verification is not applicable: this changes desired-state wording and validation only. Repeat with:

cd /workspaces/atrinik/workspace/worktrees/github-settings/issue-22-tools-mit-default
bin/validate
bash -n bin/validate tests/validate-community-health.sh
shellcheck bin/validate tests/validate-community-health.sh
actionlint
git diff --check

Blocker

• atrinik/atrinik#378 and the owning atrinik/tools#22 transition must land before this draft can deploy.