Remove unused escrow sync interval variable and streamline the Horizon
mode validation logic by using early returns instead of nested
conditionals with unreachable branches.

…ng fails

Add contextual information (notification id and signer address) to the
error when collection_id parsing fails, making debugging easier when
receipt notifications contain malformed data.

Also consolidates the SUBGRAPH_SERVICE_ADDRESS test constant to avoid
duplication across test modules.

…mode is required

Remove unreachable legacy fallback branch in sender account initialization.
Since the agent now requires Horizon mode, the denylist check is always
performed against tap_horizon_denylist.

…lpers

- Remove unreachable legacy fallback branch in sender denylist check since
  Horizon mode is now required
- Extract duplicated deny state retry loops into `wait_for_deny_state` helper
  for more robust and readable tests

Clarify that Horizon mode is now required throughout tap-agent:
- Update error messages to remove references to disabling Horizon
- Simplify tap_mode field documentation since legacy mode is removed
- Add context to legacy metric counters explaining backwards compatibility

The startup error message suggested users could disable Horizon via config,
but this option is no longer available since Horizon mode is now required.

Re-export TAP_EIP712_DOMAIN and VERIFIER_ADDRESS from test_assets instead
of duplicating the definitions in tap-agent's test module.

… required

Remove redundant `is_horizon()` conditionals that were always true since
the agent now requires Horizon mode at startup. Also convert denylist
queries to runtime execution to avoid compile-time database dependency.

Use `wait_for_deny_state` helper in pending RAVs test to account for
async message processing. Update snapshot for allocation update test
to reflect actual message ordering.

…ering

Use `wait_for_deny_state` helper in pending RAVs test to account for
async message processing. Remove flaky snapshot assertion that depended
on specific message ordering between async watchers.

…rizon tables

During migration from legacy allocations to Horizon, some receipts and RAVs may
contain 20-byte allocation IDs instead of 32-byte collection IDs. Instead of
panicking on these invalid entries, skip them with a warning to allow the system
to continue processing valid receipts.

Now that Horizon mode is required, the V1 receipts domain is no longer needed.

All TAP receipt handling now uses Horizon V2 receipts exclusively.
Legacy V1 tests and helpers are no longer needed since V1 receipt
support was removed in prior commits.

Remove legacy V1 receipt handling from the service crate, requiring only
V2 escrow accounts. This simplifies the TAP receipt processing pipeline
by eliminating the dual V1/V2 domain separator logic and consolidating
on the Horizon-compatible receipt format.

…pport

Remove the Legacy network version type and all V1-specific code paths
from tap-agent. The AllocationId enum is now a simple wrapper around
CollectionId. This removes ~900 lines of legacy RAV/receipt handling,
V1 escrow subgraph client, and dual-version metrics.

…port

Remove V1 variants and Option wrappers throughout the codebase now that
TAP V2 (Horizon) is required. This eliminates version branching in receipt
handling, RAV aggregation, and database queries.

Remove V1/V2 versioning terminology and migration references now that
legacy V1 receipt support has been dropped. Horizon is now the only
supported production mode.

Rename `derive_key_pair_v1`/`derive_key_pair_v2` to
`derive_key_pair_primary`/`derive_key_pair_fallback` to better describe
their roles rather than suggesting a versioning relationship with the
recently removed TAP V1/V2 receipt types.

…d param

Simplify startup validation since Horizon mode is now always required,
making the DIPS-specific horizon check redundant. Also remove unused
allocation_id parameter from tap_allocation_redeemed_watcher.

Horizon is now mandatory—configs with `horizon.enabled = false` are
rejected at validation time. The default value is changed to `true`
to match this requirement.

Config examples and defaults now include the required Horizon addresses
(subgraph_service_address, receipts_verifier_address_v2) that must be
set for operation.

Remove leftover "V1 tests removed" comments and update documentation to
use consistent language for the deprecated verifier address field.

Since Horizon mode is mandatory, the escrow accounts v2 watcher is
always present. Remove Option wrapper to simplify code paths and fail
fast if the watcher is missing.

Since Horizon mode is now mandatory, remove redundant "When
horizon.enabled = true" prefix from error messages. Also add TODO for
eventual removal of 20-byte allocation ID migration fallback.

Add `horizon_receipts_verifier_address()` helper to `BlockchainConfig`
that enforces the validation requirement for `receipts_verifier_address_v2`,
reducing duplication and making the contract clearer.

Mark `receipts_verifier_address` as deprecated with a compiler warning
since Horizon mode now uses `receipts_verifier_address_v2` exclusively.

The subgraph query API returns Result<Data, Error>, not
Result<Result<Data, Error>, Error>. Several match patterns were
incorrectly nested after the V1 removal refactor. Also adds explicit
type annotation for redeemed_ids vec to resolve type inference.

Tests no longer need to mock the escrow subgraph since V1 receipt
handling was removed. Also renames mock variable to reflect its
actual purpose (network subgraph for redeemed allocation checks).

Add comprehensive tests covering RAV requests, allocation closure,
unaggregated fee calculation, invalid receipt handling, and edge cases
for the Horizon-only TAP protocol implementation.

Users can now omit the deprecated receipts_verifier_address field from
their config files entirely. This reduces config clutter as the field
was only kept for backward compatibility and is not used since the
switch to Horizon receipts.

Error messages now explain that Horizon is required, rather than just
stating that fields must be set, making it clearer why configuration
is needed.

Drain startup messages before asserting on periodic reconciliation
and tolerate interleaved messages that may arrive during time
advancement.

Remove unnecessary Option wrapper from subgraph_service_address() since
Horizon mode is now required. Also fix typo in receipts_len variable and
remove obsolete TODO comment.

The receipts_verifier_address_v2 field is now a required Address instead
of Option<Address>, enforced at config load time rather than runtime
validation. This simplifies accessor methods and removes unnecessary
Option handling throughout the codebase.

…eceipts

Replace the TapReceipt enum (which only had a V2 variant) with a newtype
struct, removing the unnecessary match arms and accessor methods across
receipt handling, TAP checks, and agent code.