Tests verify:
- ARROW_STREAM format passes INLINE disposition + ARROW_STREAM format
- ARROW format passes EXTERNAL_LINKS disposition + ARROW_STREAM format
- Default JSON format does not pass disposition or format overrides

The server-side ARROW_STREAM format added in the previous commit was
not exposed to the frontend or typegen:

- Add "ARROW_STREAM" to AnalyticsFormat in appkit-ui hooks
- Add "arrow_stream" to DataFormat in chart types
- Handle "arrow_stream" in useChartData's resolveFormat()
- Make typegen resilient to ARROW_STREAM-only warehouses by
  retrying DESCRIBE QUERY without format when JSON_ARRAY is rejected

Co-authored-by: Isaac
Signed-off-by: James Broadhead <jamesbroadhead@gmail.com>

…compatibility

ARROW_STREAM with INLINE disposition is the only format that works
across all warehouse types, including serverless warehouses that reject
JSON_ARRAY. Change the default from JSON to ARROW_STREAM throughout:

- Server: defaults.ts, analytics plugin request handler
- Client: useAnalyticsQuery, UseAnalyticsQueryOptions, useChartData
- Tests: update assertions for new default

JSON and ARROW formats remain available via explicit format parameter.

Co-authored-by: Isaac
Signed-off-by: James Broadhead <jamesbroadhead@gmail.com>

When using the default ARROW_STREAM format, the analytics plugin now
automatically falls back through formats if the warehouse rejects one:
ARROW_STREAM → JSON → ARROW.

This handles warehouses that only support a subset of format/disposition
combinations without requiring users to know their warehouse's
capabilities. Explicit format requests (JSON, ARROW) are respected
without fallback.

Co-authored-by: Isaac
Signed-off-by: James Broadhead <jamesbroadhead@gmail.com>

…ne-support

Previously, _transformDataArray unconditionally called updateWithArrowStatus
for any ARROW_STREAM response, which discards inline data and returns only
statement_id + status. This was designed for EXTERNAL_LINKS (where data is
fetched separately) but broke INLINE disposition where data is in data_array.

Changes:
- _transformDataArray now checks for data_array before routing to the
  EXTERNAL_LINKS path: if data_array is present, it falls through to the
  standard row-to-object transform.
- JSON format now explicitly sends JSON_ARRAY + INLINE rather than relying
  on connector defaults. This prevents the connector default format from
  leaking into explicit JSON requests.
- Connector defaults reverted to JSON_ARRAY for backward compatibility with
  classic warehouses (the analytics plugin sets formats explicitly).
- Added connector-level tests for _transformDataArray covering ARROW_STREAM
  + INLINE, ARROW_STREAM + EXTERNAL_LINKS, and JSON_ARRAY paths.

Co-authored-by: Isaac
Signed-off-by: James Broadhead <jamesbroadhead@gmail.com>

Some serverless warehouses return ARROW_STREAM + INLINE results as base64
Arrow IPC in `result.attachment` rather than `result.data_array`. This adds
server-side decoding using apache-arrow's tableFromIPC to convert the
attachment into row objects, producing the same response shape as JSON_ARRAY
regardless of warehouse backend.

This abstracts a Databricks internal implementation detail (different
warehouses returning different response formats) so app developers get a
consistent `type: "result"` response with named row objects.

Changes:
- Add apache-arrow@21.1.0 as a server dependency (already used client-side)
- _transformDataArray detects `attachment` field and decodes via tableFromIPC
- Connector tests use real base64 Arrow IPC captured from a live serverless
  warehouse, covering: classic JSON_ARRAY, classic EXTERNAL_LINKS,
  serverless INLINE attachment, data_array fallback, and edge cases

Co-authored-by: Isaac
Signed-off-by: James Broadhead <jamesbroadhead@gmail.com>

Python implementation of the AppKit backend using FastAPI, providing
the same HTTP API surface as the TypeScript version for all plugins:
analytics (SSE query streaming), files (11 endpoints), and genie
(3 SSE endpoints). Includes full test suite (48 unit + 41 integration
tests), SSE streaming infrastructure with reconnection support,
contextvars-based user context, interceptor chain (retry/timeout/cache),
and Databricks SDK connector wiring.

Co-authored-by: Isaac

- Fix path traversal in SPA static file serving (use resolve() + prefix check)
- Fix upload endpoint OOM: stream body with running size counter
- Fix CacheInterceptor to actually use TTL (was storing forever)
- Fix StreamManager reconnection: persist EventRingBuffer per stream_id
- Fix _UserContextProxy: only wrap async methods, leave sync methods alone
- Fix _load_query path traversal: reject /, \, .. in query_key
- Fix Content-Disposition header injection: sanitize filename
- Fix format_buffered_event: apply sanitize_event_type on replay
- Fix ruff target-version to match requires-python (py312)
- Fix __main__.py: load dotenv, use APPKIT_HOST env var
- Add abort_all() implementation to StreamManager

Co-authored-by: Isaac

…es, path traversal

- Fix OBO: create per-request WorkspaceClient from x-forwarded-access-token
  instead of reusing global service-principal client for all routes
- Fix ARROW format: use EXTERNAL_LINKS disposition and emit arrow event
  with statement_id (matching TS FORMAT_CONFIGS)
- Fix SQL connector: check for FAILED/CANCELED/CLOSED states after polling
  and raise with error message instead of returning empty result
- Fix FilesConnector.resolve_path: reject path traversal (..) sequences
- Update all file/genie endpoints to use per-request user client

Co-authored-by: Isaac

…aceId

- Add pyarrow-based Arrow IPC attachment decoding (decode_arrow_attachment)
  matching TS _transformArrowAttachment for serverless warehouse support
- Implement get_arrow_data: download external link chunks via httpx
- Use transform_result() in analytics handler for unified result processing
- Add maxSize enforcement to FilesConnector.read()
- Auto-inject workspaceId parameter in process_query_params when query
  references :workspaceId
- Add pyarrow and httpx to runtime dependencies

Co-authored-by: Isaac

…→ ARROW)

Mirrors the TS _executeWithFormatFallback: when the default ARROW_STREAM
format is rejected by a warehouse (classic warehouses don't support
INLINE + ARROW_STREAM), automatically falls back through JSON then ARROW.
Verified working against live Databricks SQL Warehouse.

Co-authored-by: Isaac