Refactor knowledge.md into AGENTS.md + docs/ (#480) #5992

Job	Run time
build-and-check	3m 0s
test-integration-packages/billing	1m 9s
test-integration-packages/internal	1m 19s
test-integration-sdk	1m 28s
test-integration-web	49s
test-integration-cli	50s
test-integration-packages/agent-runtime	53s
test-packages/billing	49s
test-integration-common	42s
test-common	48s
test-sdk	46s
test-cli	1m 0s
test-packages/agent-runtime	51s
test-packages/internal	50s
test-web	53s
test-.agents	43s
	16m 50s

Provide feedback