Panora swapper #12494

Panora swapper, PR 2 (same chain Aptos swaps), stacks on #12493

Intra Aptos swaps through the Panora aggregator, our first same chain swapper on Aptos.

Docs: https://docs.panora.exchange
API: POST https://api.panora.exchange/swap, x-api-key header (public key from their docs)
PR: #12492 (only the last two commits are new to review, the rest is #12493)

Scope

• Aptos only, APT and Aptos coins, same chain swaps
• Behind VITE_FEATURE_PANORA_SWAP, off in production
• Out of scope: affiliate fee collection (blocked on DAO treasury, BIZ-35), dedicated API key and partnership (BIZ-36)

Key implementation details

• The Panora API deals in human readable token amounts both ways, NOT base units. Amounts are converted at the boundary with fromBaseUnit / toBaseUnit, verified against the live API
• integratorFeePercentage sent without integratorFeeAddress is still deducted from the user but kept by Panora (verified live in the on chain router args). Never send the percentage alone. Gated behind PANORA_INTEGRATOR_FEE_ADDRESS in PanoraSwapper/utils/constants.ts, unset until the DAO has an Aptos treasury address
• Transactions built as BCS SimpleTransaction via AptosChainAdapter.buildEntryFunctionApiTransaction, a generic entry function builder added by this PR (buildSendApiTransaction now delegates to it)
• Trade status polled on chain via checkAptosSwapStatus, same pattern as the Cetus swapper on Sui
• The API key contains # characters: the value in .env must stay double quoted or dotenv truncates it at the first # and every quote fails with a 401
• Native APT address for the Panora API is 0xa
• The public API is occasionally flaky (one poll fails, the next succeeds), a dedicated key may help (BIZ-36)

Registration checklist (shipped in the PR, per the swapper integration contract)

• SwapperName.Panora, swappers record, default slippage 0.5%
• Feature flag VITE_FEATURE_PANORA_SWAP: config validation, .env files, preferences slice, test mocks
• VITE_PANORA_API_KEY in SwapperConfig, config validation, public-api env
• CSP entry headers/csps/defi/swappers/Panora.ts
• Swapper icon
• getEnabledSwappers entry + isCrossAccountTradeSupported (false)

Validation (definition of done)

• Aptos chain integration #12493 merged first (this PR is stacked on it)
• CI workflows approved and green
• Engineering review approved, merged to develop
• On a local build with both flags on: APT to USDC quote shows Panora as protocol with a sane rate
• Reverse direction (USDC to APT) and a non stable pair (APT to amAPT) quote correctly
• One swap executed end to end, status goes from pending to complete (already done once on mainnet from the trade UI during development, redo after merge)
• No ShapeShift fee line appears in the quote while PANORA_INTEGRATOR_FEE_ADDRESS is unset

Already verified during development: multi pair quotes, one mainnet swap executed end to end with the received amount matching the quote exactly, on chain status polling through to completion. Screenshots in the PR.