Verification: Init dev env

issue-1 declared test-planning away, so the proof lives here. The checks are structural: this change adds config and docs, no code.

Verification results

What was verified	Command	Outcome	Evidence
.the-loop/ holds exactly the three files the issue asks for	ls -A .the-loop	pass	checks.md
.claude/settings.json is identical to the-loop's reference settings	curl -sL <reference raw url> | diff - .claude/settings.json	pass	checks.md
The settings register the the-loop marketplace and enable the plugin	jq -e '.enabledPlugins["the-loop@the-loop"] and .extraKnownMarketplaces["the-loop"].source.repo=="MadaraUchiha-314/the-loop"'	pass	checks.md
harness-config.yaml and collaborators.yaml validate against the plugin's schemas (19.28.0)	uv run --with pyyaml --with jsonschema python validate.py	pass	checks.md
manifest.yaml is the plugin's manifest, unchanged	diff $PLUGIN/.the-loop/manifest.yaml .the-loop/manifest.yaml	pass	checks.md
The docs trees /the-loop:init creates exist	ls -d docs/*/	pass	checks.md
No CLI config was scaffolded (out of scope per the issue)	ls -A .the-loop (no cli-config.yaml)	pass	checks.md