feat(launchpad): index dev buys

[joshuakrueger-dfx]

Summary

Indexes launchpad dev buys so the seeded creator purchase shows up in token data and activity.

Changes

• abis/TokenFactory.ts — dev buy fields on the token-creation event.
• ponder.schema.ts / ponder.config.ts — persist the dev buy amount alongside the launch.
• src/ponder/launchpad.ts — handle the dev buy in the creation handler.
• src/api/controllers/launchpad.ts + activity.ts — surface dev buy in token responses and the activity feed.
• .env.example updated.

Part of the dev buy stack

• bapp — dev buy at token creation (atomic, Permit2): feat(launchpad): dev buy at token creation bapp#772
• api — exposes dev buy fields in swagger: docs(swagger): expose launchpad dev buy fields api#268

[Danswar]

Dev buy stack — linking the related PRs:

• Indexer (this PR): feat(launchpad): index dev buys #140
• Frontend: feat(launchpad): dev buy at token creation bapp#772
• Swagger docs: docs(swagger): expose launchpad dev buy fields api#268

Shared blocker: this PR indexes a DevBuyExecuted event that the deployed TokenFactory doesn't emit. The event ABI is stubbed locally here (DevBuyExecutedAbi in abis/TokenFactory.ts) because @juiceswapxyz/launchpad doesn't export it — same reason bapp#772 stubs the function ABI. I checked the live mainnet factory 0xF5E0…28b9 bytecode: the DevBuyExecuted topic (0x25d60dba…) is not present, so the handler would never fire today.

Not harmful to merge (it just wouldn't index anything yet), but the stack is gated on the contract: write → deploy → republish the package, then ponder#140 → api#268 → bapp#772.