chore(deps)(deps): bump a2a-sdk from 0.3.26 to 1.2.1 in /sdk

[dependabot]

Bumps a2a-sdk from 0.3.26 to 1.2.1.

Release notes

Sourced from a2a-sdk's releases.

v1.2.1

1.2.1 (2026-09-30)

Bug Fixes

• server: use keyset cursors for ListTasks page tokens (#1282) (b7cba7c), closes #1280

v1.2.0

1.2.0 (2026-09-29)

Features

• rest: serve HTTP+JSON responses as application/a2a+json (#1274) (dc5a5da)
• server: add caching headers to the agent card endpoint (#1272) (83d7f5d)
• server: add multi-replica cluster mode (#1281) (942d621)
• server: add opt-in validation of message media types against the agent card (#1269) (8037b24)

Bug Fixes

• compare in-memory task timestamps numerically (#1233) (0d5473c)
• server: ignore unrecognized request fields and fix parse-error data shape (#1273) (83f1cf8)
• server: reject a message whose contextId disagrees with its task (#1270) (c25022f)
• server: reject terminal-task operations with UnsupportedOperationError (#1268) (6cce91b)
• server: send PushNotificationConfig.authentication as an Authorization header (#1271) (5751d31), closes #585

Documentation

• samples: add Agent Card signing sample (#1198) (f3ac824)

v1.1.5

1.1.5 (2026-09-21)

Bug Fixes

• deps: support protobuf 7 (#1260) (67ba0a4)
• replace deprecated FieldDescriptor.label with is_repeated in proto_utils (#1158) (4554e2d)
• server: avoid out-of-range datetime task ordering (#1220) (d55a3d3)

v1.1.4

1.1.4 (2026-09-07)

Features

• itk: register itk-python-v10-agent as a uv workspace member and update dependency version markers (#1203) (6eee895)

... (truncated)

Changelog

Sourced from a2a-sdk's changelog.

1.2.1 (2026-09-30)

Bug Fixes

• server: use keyset cursors for ListTasks page tokens (#1282) (b7cba7c), closes #1280

1.2.0 (2026-09-29)

Features

• rest: serve HTTP+JSON responses as application/a2a+json (#1274) (dc5a5da)
• server: add caching headers to the agent card endpoint (#1272) (83d7f5d)
• server: add multi-replica cluster mode (#1281) (942d621)
• server: add opt-in validation of message media types against the agent card (#1269) (8037b24)

Bug Fixes

• compare in-memory task timestamps numerically (#1233) (0d5473c)
• server: ignore unrecognized request fields and fix parse-error data shape (#1273) (83f1cf8)
• server: reject a message whose contextId disagrees with its task (#1270) (c25022f)
• server: reject terminal-task operations with UnsupportedOperationError (#1268) (6cce91b)
• server: send PushNotificationConfig.authentication as an Authorization header (#1271) (5751d31), closes #585

Documentation

• samples: add Agent Card signing sample (#1198) (f3ac824)

1.1.5 (2026-09-21)

Bug Fixes

• deps: support protobuf 7 (#1260) (67ba0a4)
• replace deprecated FieldDescriptor.label with is_repeated in proto_utils (#1158) (4554e2d)
• server: avoid out-of-range datetime task ordering (#1220) (d55a3d3)

1.1.4 (2026-09-07)

Features

• itk: register itk-python-v10-agent as a uv workspace member and update dependency version markers (#1203) (6eee895)
• itk: use shared scenarios (#1201) (b4a0b21)

Bug Fixes

... (truncated)

Commits

• 041c17b chore(main): release 1.2.1 (#1283)
• b7cba7c fix(server): use keyset cursors for ListTasks page tokens (#1282)
• 5ca9859 chore(main): release 1.2.0 (#1266)
• 942d621 feat(server): add multi-replica cluster mode (#1281)
• dc5a5da feat(rest): serve HTTP+JSON responses as application/a2a+json (#1274)
• 83f1cf8 fix(server): ignore unrecognized request fields and fix parse-error data shap...
• 83d7f5d feat(server): add caching headers to the agent card endpoint (#1272)
• 5751d31 fix(server): send PushNotificationConfig.authentication as an Authorization h...
• c25022f fix(server): reject a message whose contextId disagrees with its task (#1270)
• 8037b24 feat(server): add opt-in validation of message media types against the agent ...
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