fix(explorer): hide private zone receipt side amounts

[snario]

Summary\n\n- Hide receipt-side summary amounts for Private Zone Withdrawal and Private Zone Deposit\n- Preserve the precise token amounts in each event detail line\n- Keep side amounts unchanged for public Zone and other receipt events\n- Apply the same presentation rule to the receipt card and TXT export\n\n## Screenshots\n\n| Before | After |\n|--------|-------|\n| | |\n\n## Test plan\n\n- pnpm check\n- pnpm check:types\n- pnpm test in apps/explorer — 125 tests passed\n- pnpm precommit\n- Browser verification against the affected receipt

[github-actions]

Bundle Size Report

Metric	Size	Δ Change
Total	5.9 MB	+1.6 MB (+38.6%)
Gzip	1.7 MB	+514.2 KB (+41.2%)
Brotli	1.5 MB	+446.2 KB (+41.1%)

Chunk changes (>1KB)

Chunk	Change
assets/chains.js (removed)	-360.7 KB
assets/tempo-queries.js	-301.0 KB
assets/core.js (removed)	-189.5 KB
assets/export-rate-limit.js (removed)	-177.3 KB
assets/engine-javascript.js (removed)	-92.9 KB
assets/decodeAbiParameters.js (removed)	-71.7 KB
assets/_hash.js	-44.1 KB
assets/AbiItem.js (removed)	-27.1 KB
assets/sha2.js (removed)	-14.7 KB
assets/queryOptions.js	-11.8 KB
assets/Bytes.js	-9.6 KB
assets/env.js	-8.9 KB
assets/fee-amm-pool-rows.js (removed)	-6.6 KB
assets/validators.js (removed)	-5.1 KB
assets/wagmi.config.js	-2.4 KB
assets/tokens.js	-1.3 KB
assets/react.js	-1.1 KB
assets/Value.js (removed)	-1.0 KB
assets/TransactionCell.js (new)	+1.1 KB
assets/jsx-runtime.js (new)	+1.1 KB
...and 38 more

Compared against main branch (baseline from 4/27/2026, 4:02:54 PM)