docs: document caching default change INTER-1988

[JuroUhlar]

• Document the breaking change: default caching strategy changed from sessionStorage to no caching (aligned with JS agent v4 default)
• Add README guidance on how to enable caching with the cache start option
• Add example showing cache={{ storage: 'sessionStorage', duration: 3600 }} for users wanting to preserve previous behavior

[github-actions]

This PR will create a patch release 🚀

3.0.1 (2026-04-20)

Bug Fixes

• update README for consistency and correct link to documentation (42f45dc)

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟢	Statements	83.21%	109/131
🟡	Branches	63.77%	44/69
🟢	Functions	80.49%	33/41
🟢	Lines	82.81%	106/128

Test suite run success

21 tests passing in 15 suites.

Report generated by 🧪jest coverage report action from c835b5f

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St	File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
🟢	All files	83.2	63.76	80.48	82.81
🟢	src	88.7	75.86	83.33	88.33
🟢	detect-env.ts	90	83.33	100	90	15,85
🟢	env.ts	100	100	100	100
🟢	env.types.ts	85.71	40	50	83.33	14
🟡	...nt-context.ts	75	100	0	75	8
🟡	get-env.ts	60	0	100	60	8-9
🟢	ssr.ts	100	100	100	100
🟢	...sitor-data.ts	95.65	100	80	95.65	100
🟢	src/components	92.5	61.53	91.66	92.3
🟢	...-provider.tsx	91.17	58.33	90	90.9	53,58,96
🟢	...vironment.tsx	100	100	100	100
🟡	src/utils	58.62	42.85	63.63	58.62
🟡	...-is-truthy.ts	50	50	100	50	3
🟡	to-error.ts	66.66	50	100	66.66	6
🟢	use-const.ts	100	50	100	100	4
🟢	...mise-store.ts	92.3	75	100	92.3	7
🔴	wait-until.ts	0	0	0	0	8-19