Falcon-1024 accounts pay an extra 2x the min fee per transaction, so the
examples' "Send 0 ALGO" with the suggested fee was rejected for them.

- Simulate the payment with emptyTransactionSigner, allowEmptySignatures
  and fixSigners, and set the fee from the group's groupUsage (millionths
  of the min fee), keeping the suggested fee if it's higher
- Apply it in all seven examples with a small estimateFee helper
- e2e: fake POST /v2/transactions/simulate with an algosdk-encoded
  response (group-usage 1000000) for the test transaction
- Signing guide: add Estimating Fees, covering groups, wallets without
  empty signatures and per-byte fees under congestion; list
  emptyTransactionSigner in the useWallet reference

isSignedTxn only recognized an ed25519 `sig`. Adapters use it to skip
transactions that are already signed when they're given encoded
transactions, so a group with a transaction signed by a multisig, a logic
sig or a post-quantum (Falcon) key was treated as unsigned and crashed in
decodeUnsignedTransaction ("Unrecognized transaction type").

- Accept `sig`, `msig`, `lsig` or `pqsig`, as `SignedTransaction` does
- Test each signature type with transactions algosdk signs and encodes
- Test the Mnemonic adapter skipping a logic-sig-signed transaction in an
  encoded group

isSignedTxn only recognized an ed25519 `sig`. Adapters use it to skip
transactions that are already signed when they're given encoded
transactions, so a group with a transaction signed by a multisig, a logic
sig or a post-quantum (Falcon) key was treated as unsigned and crashed in
decodeUnsignedTransaction ("Unrecognized transaction type").

- Accept `sig`, `msig`, `lsig` or `pqsig`, as `SignedTransaction` does
- Test each signature type with transactions algosdk signs and encodes
- Test the Mnemonic adapter skipping a logic-sig-signed transaction in an
  encoded group

Bullseye is no longer in LTS and Claude believes this is why goreleaser
is failing. Other changes address warnings from docker and deprecated
chown separator

Bump docker image base from bullseye to trixie

Bullseye is no longer in LTS and Claude believes this is why goreleaser
is failing. Other changes address warnings from docker and deprecated
chown separator

Bullseye is no longer in LTS and Claude believes this is why goreleaser
is failing. Other changes address warnings from docker and deprecated
chown seperator