refactor(webapp): use remaining design system primitives

[dev-jodee]

Summary

• migrate remaining supported action surfaces to @solana/design-system Button
• replace remaining text/number native inputs with TextInput while keeping checkboxes local
• use SegmentedControl for the collection detail view toggle
• leave local Card, Dialog, Label, Alert, DropdownMenu, and unsupported button variants in place

Test Plan

• just fmt-check
• just lint-check
• pnpm --filter webapp build
• pnpm --filter webapp test

[github-actions]

Compute Unit Report

Instruction	Samples	Min CUs	Max CUs	Avg CUs	Est Cost (Low) [SOL]	Est Cost (Med) [SOL]	Est Cost (High) [SOL]
cancel_subscription	11	1805	2129	2013	0.000005000	0.000005080	0.000006006
close_subscription_authority	7	1881	1916	1886	0.000005000	0.000005075	0.000005943
create_fixed_delegation	38	3621	12621	5742	0.000005001	0.000005229	0.000007871
create_plan	84	3540	11053	5079	0.000005001	0.000005203	0.000007539
create_recurring_delegation	27	3640	8145	4591	0.000005001	0.000005183	0.000007295
delete_plan	8	416	416	416	0.000005000	0.000005016	0.000005208
init_subscription_authority	142	7431	22525	12026	0.000005003	0.000005481	0.000011013
revoke_delegation	19	318	585	420	0.000005000	0.000005016	0.000005210
subscribe	21	6670	17170	8323	0.000005002	0.000005332	0.000009161
transfer_fixed	6	10094	11597	10596	0.000005003	0.000005423	0.000010298
transfer_recurring	17	10206	13297	11384	0.000005003	0.000005455	0.000010692
transfer_subscription	10	10441	11976	10630	0.000005003	0.000005425	0.000010315
update_plan	21	424	503	476	0.000005000	0.000005019	0.000005238

Generated: 2026-04-30