feat: update examples to be compatible with 8.x chain

[prashantasdeveloper]

Summary

Updates all SDK examples for Polymesh chain v8 and @polymeshassociation/polymesh-sdk v30 / local-signing-manager v4. All 24 examples were run against a local dev node and adjusted for API changes, idempotent re-runs, and common local-chain constraints. The README is expanded with setup instructions, env var docs, an example index, and troubleshooting.

Changes

Dependencies & tooling

• Bump @polymeshassociation/polymesh-sdk to 30.0.0
• Bump @polymeshassociation/local-signing-manager to ^4.1.1
• Add Yarn 4 config (.yarnrc.yml, packageManager in package.json)

Shared utilities

• client.ts: default dev account uses { mnemonic: '//Alice' } instead of { uri: '//Alice' }
• utils.ts: add getAssetHolderLabel() for settlement AssetHolder types (Account vs Portfolio)

Example updates

Example	Key changes
subsidy.ts	approveSubsidy / acceptSubsidy flow; resilient handling of existing/missing subsidies
transferRestrictions.ts	Rewritten for setStats() + setRestrictions() API
settlements.ts	party instead of identity on affirmations; configurable asset via argv; resilient affirm
createToken.ts	documents.add() / documents.remove() instead of set() for removal
externalAgents.ts	TxGroup.AssetManagement; resilient group create/invite/set
manageSecondaryKeys.ts	Auto-generate unlinked account; resilient invite/permissions/remove
claims.ts	Graceful skip when getCddClaims() is unsupported on v8
batchTransactions.ts	Unique names via timestamp; second createPortfolio instead of deprecated freeze
dividendDistributions.ts	DIVIDEND_CURRENCY env/argv; improved timing and graceful skip for claim/reclaim
staking.ts	Use getSigningAccounts(); resilient re-runs (already bonded, etc.)
investInSto.ts	v30 offerings API; distinct investor identity; settlement funding; compliance pause
stos.ts	DIVIDEND_CURRENCY for raising currency; auto-create VenueType.Sto venue; optional --close
portfolios.ts / portfolioCustodians.ts	Unique portfolio names; asset ID via argv; graceful custodian skips
securityTokenCaa.ts	Resilient agent invite

Environment & docs

• Expand .env.sample with DIVIDEND_CURRENCY, BOB_SEED, and inline docs
• Rewrite README.md: setup, env var table, example index (all 24 scripts), run order, local dev notes, troubleshooting

Test plan

All 24 examples verified against a local node (ws://localhost:9944):

cp .env.sample .env
yarn install

# Create or use an asset you control
yarn run-example src/examples/createToken.ts MY_TICKER

# STO flow
yarn run-example src/examples/stos.ts <ASSET_ID>
yarn run-example src/examples/investInSto.ts <ASSET_ID>

# Asset-scoped examples
yarn run-example src/examples/<example>.ts <ASSET_ID>

# Subsidy
yarn run-example src/examples/subsidy.ts account=<BOB_ADDRESS>

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud