finalize-pure-go-sqlite-migration-cleanup - #785

* modernc sqlite migration prep

* migrate-embedded-sqlite-to-pure-go-modernc (#783)

* docs(sqlfuncs): mirror CLAUDE.md as AGENTS.md for all agent sessions

Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* deps: adopt any-sdk pure-Go sqlite backend, drop mattn/cgo fork replace

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* ci: retire cgo - CGO_ENABLED=0, drop C toolchains and sqlite_stackql tag, add per-artifact function smoke

Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* docs+test: modernc backend invariants, release notes draft, robot ext-function smoke scenario

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* deps: bump any-sdk to alpha02 (aws_policy_equal tags parity, boolean decltype); pin sqlite_version fixture to 3.53.4

Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* burn: remove executed migration work order

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Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* finalize-pure-go-sqlite-migration-cleanup (#785)

* retire remaining cgo configuration and stale migration artifacts

Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* preserve migration smoke-test documentation

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Co-authored-by: jeffreyaven <5146499+jeffreyaven@users.noreply.github.com>

* shard-postgres-docker-robot-tests

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* keep-stateful-robot-tests-in-one-shard

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* rename-release-process-doc-without-spaces

Rename `docs/stackql release process.md` to
`docs/stackql_release_process.md` per review, and update the three
references to it (two workflow header comments and the mcpb packaging
notes) so nothing points at the old name.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* move-extension-function-smoke-to-robot

Remove the six workflow-level extension function smoke steps from
build.yml per review. The check lives in the robot scenario
`Sqlite Extension Functions Smoke Working`, which now carries the
stronger aws_policy_equal comparison the workflow steps used (Version
plus scalar-vs-array Resource), so nothing is lost in the move.

The scenario runs wherever the functional suite runs: winbuild,
linuxtest, linuxarmbuild, macosbuild, wsltest and the docker sqlite leg.
winarmsmoke and macosarmbuild have no robot harness, so the check is no
longer exercised in those two jobs.

Also drop the stale "cgo" wording from the winarmsmoke comment.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* assert-shard-completeness-after-docker-tests

Sharding splits one robot run across several dockertest legs, so no
single leg can attest that the whole suite ran. Add a dockertestverify
job that runs once all legs conclude and fails unless, for each
(platform, db backend) group, the shards together account for every
functional test exactly once.

- Each robot-running dockertest leg uploads its output.xml; unsharded
  legs upload as shard 1 of 1.
- robot_shard.py gains a verifier. The expected tests are parsed from
  test/robot/functional with no shard modifier applied, then compared
  as a multiset against the union of the shard reports, so the total
  count and each individual test are checked independently.
- Anything that prevents verification fails it: absent shard, absent
  output.xml, inconsistent shard counts, a NOT RUN test, an expected
  group with no reports, or reports from a group that is not listed.
- dockermerge now needs dockertestverify, so an image cannot be pushed
  past a failed verification.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* run-robot-suite-on-arm-runners

Per review: now that GitHub hosts arm64 macOS and Windows runners, run
the robot functional suite on both rather than leaving the extension
function check unexercised there.

- macosarmbuild: mirror the macosbuild robot harness (libpq, python
  deps, registry rewrite, certificates, robot run, report upload). The
  libpq path is resolved with `brew --prefix` because homebrew's prefix
  differs on Apple Silicon.
- winarmsmoke: mirror the winbuild robot harness against the amd64
  binary under x64 emulation. Python is x64 because psycopg2-binary,
  psycopg-binary and cryptography publish no win_arm64 wheels. The job
  now checks out the repo (before the artifact downloads, since checkout
  cleans the workspace) and moves from the short to the standard job
  timeout.
- winbuild: upload the MCP client as an artifact so the MCP scenarios
  run in winarmsmoke rather than being skipped.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

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