Clean up pyi_hashes.json annoyances

[masenf]

Building a component package previously rewrote pyi_hashes.json, replacing the entire registry with only the package being built and wiping every other entry. A bare uv build packages/<pkg> (or the build triggered by uv sync) was enough to leave the registry with a single hash. The build hooks now only emit the .pyi stubs shipped in the wheel and never touch the registry; maintaining pyi_hashes.json is reserved for the update-pyi-files pre-commit step.

scripts/make_pyi.py:

• --force regenerates every default target, ignoring the incremental markers.
• Explicit targets are regenerated and merged into pyi_hashes.json (never pruned) and leave the .pyi_generator_last_run / .pyi_generator_diff markers untouched; only a default run with no targets owns those markers.
• An unreachable last-run commit (branch switch or rebase) now forces a full regeneration instead of diffing against a meaningless base.
• --check fails if any pyi_hashes.json entry has no corresponding .py source, and is wired into the pre-commit CI job so a deleted component can't leave a stale entry behind (explicit-target runs merge rather than prune).

pyi_generator.scan_all() gained a prune_stale flag that decouples "replace the whole registry" from "scan everything", so a partial run can regenerate its targets without dropping unrelated hashes.

[codspeed-hq]

Merging this PR will not alter performance

✅ 28 untouched benchmarks

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_{Comparing masenf/annoying-pyi-hashes (da258c1) with main (9c8a0ae)}

[greptile-apps]

Greptile Summary

This PR fixes a long-standing issue where building any single component package (or running uv sync) would silently replace all of pyi_hashes.json with only that package's entries. The fix decouples "scan a subset of targets" from "replace the whole registry" by introducing a prune_stale flag in scan_all(), setting the build-hook entrypoint to use_json=False, and refactoring scripts/make_pyi.py into a proper CLI with --force/--check modes.

• pyi_generator.py: adds prune_stale parameter to scan_all(); the __main__ block that build hooks invoke now uses use_json=False, so wheel builds never touch pyi_hashes.json.
• scripts/make_pyi.py: refactored into main() with argparse; explicit-target runs merge into the registry, default runs prune it when regenerating everything, and an unreachable last-run commit now triggers a safe full regen instead of a broken incremental diff.
• CI: a new --check step after pre-commit fails the build if any pyi_hashes.json entry references a deleted .py source; comprehensive unit tests cover all dispatch branches.

Confidence Score: 5/5

Safe to merge — changes are narrowly scoped to pyi-generation tooling with no impact on runtime Reflex behavior.

All three code paths are exercised by new unit tests, the regression test covers the core bug scenario end-to-end, and the CI guard catches future drift. Only a minor UX gap exists where --check and --force can be combined without a warning.

No files require special attention.

Important Files Changed

Filename	Overview
scripts/make_pyi.py	Major refactor: adds argparse, --force/--check flags, commit-reachability guard, and separates explicit-target runs (merge) from default runs (prune). Logic is correct and well-tested.
packages/reflex-base/src/reflex_base/utils/pyi_generator.py	Adds prune_stale flag to scan_all() and changes main to use_json=False, preventing build hooks from overwriting the registry. Core fix is correct.
tests/units/test_make_pyi.py	Comprehensive unit tests covering all dispatch branches, prune vs. merge decisions, marker stamping, commit reachability, and the --check flag. Good coverage.
tests/units/reflex_base/utils/pyi_generator/test_build_hashes.py	Regression test that invokes the generator main entry point as build hooks do and asserts pyi_hashes.json is untouched. Well-structured.
.github/workflows/pre-commit.yml	Adds a post-pre-commit --check step to fail CI when pyi_hashes.json contains stale entries. Correct placement and flags.
news/6614.bugfix.md	Changelog entry, no code changes.

_{Reviews (1): Last reviewed commit: "Clean up pyi_hashes.json annoyances" | Re-trigger Greptile}

[masenf]

the two news fragments seem to overlap too much, can you make each one more focused