feat(rust): port stack list + stack open to native Rust

[jd]

The Rust binary now serves mergify stack list [--json] [--verbose] and mergify stack open [<commit>] natively.
The Python implementations
(mergify_cli/stack/list.py,
mergify_cli/stack/list_schema.py,
mergify_cli/stack/open.py, the click registrations, and
test_{list,open}.py) are removed.

New shared infrastructure that the remaining slices
(stack push) will reuse:

• mergify_stack::changes::classify — full per-commit
  classifier that buckets each local commit as
  Create / Update / SkipMerged / SkipUpToDate,
  the same shape Python's get_changes returns. Also
  surfaces orphan PRs (open remote changes that don't match
  any local commit). The merged-vs-remaining sync_status
  module stays for stack sync since sync only needs the
  bucket; the full classifier here is what list, open,
  and push need.

• StackContext + resolve_stack_context in the binary
  — bundles token / GitHub server / repo slug / author /
  branch prefix / trunk resolution that every API-backed stack
  subcommand runs. checkout and sync will pick this up
  in a follow-up cleanup; for now they keep their inline
  copies.

mergify stack list:

1. Runs the shared stack-context preamble.
2. Walks the local stack via local_commits::read, fetches
   the matching remote PRs via remote_changes::get_remote_changes,
   classifies via changes::classify.
3. For each entry, computes the display status
   (open / draft / merged / no_pr) from the
   classifier's action plus the PR's merged_at / draft
   fields.
4. Optionally fans out per-PR /check-runs and /reviews
   fetches and folds them into the entry's ci_* / review_*
   fields. Sequential (not concurrent) — GitHub's secondary
   rate limit on the same endpoint pool starts firing around
   ~80 concurrent calls, and a typical stack is well under
   that. stack open passes include_status=false to
   skip this.
5. Renders either JSON (serde_json::to_string_pretty of
   StackListOutput, byte-compatible with the pre-port
   --json output) or a plain-text table.

mergify stack open:

1. Runs stack::list with include_status=false.
2. None commit → leaf entry (the Python interactive picker
   defaulted there too; we leave the picker out of the port for
   now).
3. Explicit commit → git rev-parse --verify then look up
   the matching StackListEntry.
4. Hand the html_url to the OS opener: open (macOS),
   xdg-open (other Unix), cmd /C start "" (Windows).
5. PR-less commits surface StackNotFound with a hint to
   run stack push first.

Coverage: 7 changes::tests for the classifier (create /
skip-merged / amended-after-merge / skip-up-to-date / update /
orphan / closed-unmatched), 6 commands::list::tests for
the CI / review status reducers (passing / failing-over-pending
/ pending / approved / changes-requested / pending-from-comments).

Co-Authored-By: Claude Opus 4.7 noreply@anthropic.com

Depends-On: #1523

[jd]

This pull request is part of a Mergify stack:

#	Pull Request	Link
1	feat(rust): port stack note to native Rust	#1515
2	feat(rust): port stack edit + add rebase-todo machinery	#1516
3	feat(rust): port stack drop to native Rust	#1517
4	feat(rust): port stack fixup to native Rust	#1518
5	feat(rust): port stack reword to native Rust	#1519
6	feat(rust): port stack reorder + stack move to native Rust	#1520
7	feat(rust): port stack squash to native Rust	#1521
8	feat(rust): port stack checkout to native Rust	#1522
9	feat(rust): port stack sync to native Rust	#1523
10	feat(rust): port stack list + stack open to native Rust	#1524	👈

[mergify]

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🔴 ⛓️ Depends-On Requirements

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• depends-on=Mergifyio/mergify-cli#1515 [⛓️ feat(rust): port stack note to native Rust #1515 [stack]]
• depends-on=Mergifyio/mergify-cli#1516 [⛓️ feat(rust): port stack edit + add rebase-todo machinery #1516 [stack]]
• depends-on=Mergifyio/mergify-cli#1517 [⛓️ feat(rust): port stack drop to native Rust #1517 [stack]]
• depends-on=Mergifyio/mergify-cli#1518 [⛓️ feat(rust): port stack fixup to native Rust #1518 [stack]]
• depends-on=Mergifyio/mergify-cli#1519 [⛓️ feat(rust): port stack reword to native Rust #1519 [stack]]
• depends-on=Mergifyio/mergify-cli#1520 [⛓️ feat(rust): port stack reorder + stack move to native Rust #1520 [stack]]
• depends-on=Mergifyio/mergify-cli#1521 [⛓️ feat(rust): port stack squash to native Rust #1521 [stack]]
• depends-on=Mergifyio/mergify-cli#1522 [⛓️ feat(rust): port stack checkout to native Rust #1522 [stack]]
• depends-on=Mergifyio/mergify-cli#1523 [⛓️ feat(rust): port stack sync to native Rust #1523 [stack]]

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• depends-on=Mergifyio/mergify-cli#1515 [⛓️ feat(rust): port stack note to native Rust #1515 [stack]]
• depends-on=Mergifyio/mergify-cli#1516 [⛓️ feat(rust): port stack edit + add rebase-todo machinery #1516 [stack]]
• depends-on=Mergifyio/mergify-cli#1517 [⛓️ feat(rust): port stack drop to native Rust #1517 [stack]]
• depends-on=Mergifyio/mergify-cli#1518 [⛓️ feat(rust): port stack fixup to native Rust #1518 [stack]]
• depends-on=Mergifyio/mergify-cli#1519 [⛓️ feat(rust): port stack reword to native Rust #1519 [stack]]
• depends-on=Mergifyio/mergify-cli#1520 [⛓️ feat(rust): port stack reorder + stack move to native Rust #1520 [stack]]
• depends-on=Mergifyio/mergify-cli#1521 [⛓️ feat(rust): port stack squash to native Rust #1521 [stack]]
• depends-on=Mergifyio/mergify-cli#1522 [⛓️ feat(rust): port stack checkout to native Rust #1522 [stack]]
• depends-on=Mergifyio/mergify-cli#1523 [⛓️ feat(rust): port stack sync to native Rust #1523 [stack]]

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  • author = mergify-ci-bot
  • author = renovate[bot]

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• title ~= ^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert|ui)(?:\(.+\))?:

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