fix: add support for incompatible_no_implicit_file_export flag (#596)

## Summary

Adds support for Bazel's `--incompatible_no_implicit_file_export` flag
to comply with the new visibility requirements for file exports.

## Changes

- ✅ Enabled `incompatible_no_implicit_file_export` flag in
`shared.bazelrc`
- ✅ Added explicit `exports_files()` declarations for all `.bzl` files
referenced across package boundaries:
  - `bazeldoc/BUILD.bazel` - exports `defs.bzl`
  - `bzlformat/BUILD.bazel` - exports `defs.bzl`
  - `bzllib/BUILD.bazel` - exports `defs.bzl`
  - `bzlrelease/BUILD.bazel` - exports `defs.bzl`
  - `bzltidy/BUILD.bazel` - exports `defs.bzl`
  - `ci/BUILD.bazel` - exports `defs.bzl`
  - `markdown/BUILD.bazel` - exports `defs.bzl`
  - `updatesrc/BUILD.bazel` - exports `defs.bzl`
  - `shlib/rules/BUILD.bazel` - exports `execute_binary.bzl`
- ✅ Upgraded `buildifier_prebuilt` from `7.3.1` to `8.2.1.1` for
compatibility
- ✅ Added explicit `rules_python` `1.8.0` dependency to override
transitive `1.0.0` (includes [PR
#3471](bazel-contrib/rules_python#3471) fix)

## Test Plan

- [x] All 362 tests pass with `bazel test //...`
- [x] Build succeeds with the incompatible flag enabled
- [x] No visibility errors from implicit file exports

## Related Issues

Fixes #566

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: cgrindel

.bcr/patches/remove_last_green.patch

@@ -1,6 +1,6 @@
 --- a/MODULE.bazel
 +++ b/MODULE.bazel
-@@ -82,11 +82,9 @@
+@@ -86,11 +86,9 @@
      dev_dependency = True,
  )
  bazel_binaries.download(version_file = "//:.bazelversion")

MODULE.bazel

@@ -31,13 +31,17 @@ bazel_dep(
 )
 bazel_dep(
     name = "buildifier_prebuilt",
-    version = "7.3.1",
+    version = "8.2.1.1",
 )
 bazel_dep(name = "platforms", version = "1.0.0")
 bazel_dep(name = "rules_shell", version = "0.6.1")
 bazel_dep(name = "rules_multitool", version = "1.0.0")
 bazel_dep(name = "aspect_bazel_lib", version = "2.22.4")
 
+# Override transitive dependency on rules_python 1.0.0 to get
+# incompatible_no_implicit_file_export compatibility (PR #3471).
+bazel_dep(name = "rules_python", version = "1.8.0")
+
 multitool = use_extension(
     "@rules_multitool//multitool:extension.bzl",
     "multitool",

bazeldoc/BUILD.bazel

@@ -3,6 +3,8 @@ load("//bzlformat:defs.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 filegroup(

bzlformat/BUILD.bazel

@@ -3,6 +3,8 @@ load("//bzlformat/private:bzlformat_pkg.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 filegroup(

bzllib/BUILD.bazel

@@ -3,6 +3,8 @@ load("//bzlformat:defs.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 filegroup(

bzlrelease/BUILD.bazel

@@ -3,6 +3,8 @@ load("//bzlformat:defs.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 filegroup(

bzltidy/BUILD.bazel

@@ -3,6 +3,8 @@ load("@cgrindel_bazel_starlib//bzlformat:defs.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzl_library(
     name = "defs",
     srcs = ["defs.bzl"],

ci/BUILD.bazel

@@ -1,6 +1,8 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("@cgrindel_bazel_starlib//bzlformat:defs.bzl", "bzlformat_pkg")
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 bzl_library(

markdown/BUILD.bazel

@@ -3,6 +3,8 @@ load("//bzlformat:defs.bzl", "bzlformat_pkg")
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["defs.bzl"])
+
 bzlformat_pkg(name = "bzlformat")
 
 filegroup(

shared.bazelrc

@@ -10,6 +10,9 @@ build --incompatible_strict_action_env=true
 # Don't allow empty glob patterns by default
 build --incompatible_disallow_empty_glob
 
+# Require explicit exports_files() declarations instead of implicit file exports
+build --incompatible_no_implicit_file_export
+
 # Enable bzlmod
 common --enable_bzlmod
 build --@cgrindel_bazel_starlib//bzlmod:enabled