feat(ENG-283): Store market and vault bump seeds in MarketHeader

[alnoki]

Changes

1. Add market_data_header (MarketHeader) and market_data_bytes
   (u8) fields to InputBufferHeader, placing market account data
   at a compile-time-known offset from r1
2. Add MARKET_DATA_NEXT, MARKET_DATA_BUMP,
   MARKET_DATA_BASE_VAULT_BUMP, MARKET_DATA_QUOTE_VAULT_BUMP,
   and MARKET_DATA_BYTES offset constants to the input_buffer
   constant group
3. Extend INIT-MARKET-PDA to initialize MarketHeader.next to
   the first allocatable byte after the header and store the
   derived market PDA bump seed
4. Extend REGISTER-MARKET to store the base and quote vault PDA
   bump seeds in MarketHeader after each INIT-VAULT call
5. Update INIT-MARKET-PDA and REGISTER-MARKET algorithm specs
   with new ensure annotations and pseudocode for the bump and
   next pointer assignments
6. Add check_market_header_bumps test helper that verifies
   next against MM_INPUT_START + MARKET_DATA_BYTES, and all
   three bump seeds against find_program_address results
7. Add solana-sbpf test dependency for the MM_INPUT_START
   constant
8. Update inputs.md prose to describe the MarketHeader overlay
   and market_data_bytes initialization target

[linear]

ENG-283