diff --git a/.editorconfig b/.editorconfig
index 0d9838d89..27247697f 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -15,25 +15,10 @@
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 # Common editor configurations for this project.
 #
-# EditorConfig defines a file format for specifying some common coding style
-# parameters. Many IDEs and editors read .editorconfig files, either natively
-# or via plugins. A few formatters also read .editorconfig; shfmt and Prettier
-# are two examples (as of early 2025).
-#
+# EditorConfig is a file format for specifying some common style parameters.
+# Many IDEs & editors read .editorconfig files, either natively or via plugins.
 # We mostly follow Google's style guides (https://google.github.io/styleguide/)
-# with very few deviations.
-#
-# Miscellaneous notes:
-#
-# - The EditorConfig property `max_line_length` is not set here because its
-#   intended behavior is poorly specified. (See the discussion in the comments
-#   at https://github.com/editorconfig/editorconfig/issues/387) It *would* have
-#   been desirable to define a project convention for the line width here, but
-#   we must instead use editor-specific configuration files to do that.
-#
-# - With few exceptions (e.g., shfmt), `.editorconfig` files are not read by
-#   linters or formatters, which means the project needs separate config files
-#   for those tools. This includes markdownlint, yamllint, and others.
+# with only a few deviations for line length and indentation in some files.
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 root = true
@@ -43,24 +28,19 @@ charset = utf-8
 indent_style = space
 insert_final_newline = true
 spelling_language = en-US
-# It would be preferable not to set tab_width, but some EditorConfig plugins
-# (e.g., Emacs's) set it equal to indent_size if it's not set otherwise.
-tab_width = 8
-# Trailing whitespace on lines is almost always noise. An exception is in
-# Markdown, where two spaces = line break; however, that's such a foot-gun in
-# practice that we avoid it. So, it's okay to set this next value globally.
 trim_trailing_whitespace = true
+max_line_length = 100
 
-[{BUILD,*.BUILD,*.bzl,*.bazel}]
+[{BUILD,*.BUILD,*.bzl,*.bazel,.bazelrc}]
 # Google doesn't have a style guideline for Bazel files. Most people use 4.
 indent_size = 4
 
 [{*.cc,*.h}]
-# This matches Google style guidelines.
+# Google style guidelines use 2.
 indent_size = 2
 
-[{*.ts,*.js}]
-# This matches Google style guidelines.
+[{*.js,*.ts}]
+# Google style guidelines use 2.
 indent_size = 2
 
 [*.json]
@@ -68,7 +48,7 @@ indent_size = 2
 indent_size = 2
 
 [*.py]
-# This matches Google style guidelines.
+# Google style guidelines use 4.
 indent_size = 4
 
 [*.rst]
@@ -78,16 +58,6 @@ indent_size = 3
 [*.sh]
 # Google style guidelines use 2.
 indent_size = 4
-# The following are used by shfmt. These bring it closer to Google's style.
-binary_next_line = true
-shell_variant = bash
-space_redirects = true
-switch_case_indent = true
-
-# If this repository has a "third_party" directory, ignore it entirely.
-# Note: shfmt also respects this if you run it with --appply-ignore.
-[third_party/**]
-ignore = true
 
 [{*.yaml,*.yml}]
 # Google doesn't have style guidelines for YAML. Most people use indent = 2.
diff --git a/.jsonlintrc b/.jsonlintrc
deleted file mode 100644
index 3f290f9a4..000000000
--- a/.jsonlintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "comments": false,
-  "compact": true,
-  "endOfLine": "lf",
-  "indent": 2,
-  "no-duplicate-keys": true,
-  "patterns": ["**/*.json"],
-  "singleQuote": false,
-  "trailing-commas": false
-}
diff --git a/.jsonlintrc.yaml b/.jsonlintrc.yaml
new file mode 100644
index 000000000..4a7f53370
--- /dev/null
+++ b/.jsonlintrc.yaml
@@ -0,0 +1,32 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# Project configuration for jsonlint (https://github.com/prantlf/jsonlint).
+# Note: there are multiple programs named jsonlint. The one targeted by this
+# config file is an updated fork of a different "jsonlint".
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+comments: false
+compact: true
+continue: true
+endOfLine: lf
+indent: 2
+log-files: false
+no-duplicate-keys: true
+patterns:
+  - '**/*.json'
+  - '!**/node_modules'
+singleQuote: false
+trailing-commas: false
diff --git a/.shellcheckrc b/.shellcheckrc
deleted file mode 100644
index 672437e78..000000000
--- a/.shellcheckrc
+++ /dev/null
@@ -1,36 +0,0 @@
-# Copyright 2025 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-# Project shellcheck configuration.
-#
-# Optional settings can be discovered by running "shellcheck --list-optional".
-# The following page includes more information about the .shellcheckrc file:
-# https://github.com/koalaman/shellcheck/wiki/Directive#shellcheckrc-file
-#
-# Note: shellcheck does not consider style factors such as indentation and
-# line length. Shfmt is used for that; its configuration is in .editorconfig.
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-# We use bash for all the scripts, so tell shellcheck to assume this dialect.
-shell=bash
-
-# Makes shellcheck include files pointed-to by the source or . statements.
-external-sources=true
-
-# Enable check for when a script uses "set -e" but a construct may disable it.
-enable=check-set-e-suppressed
-
-# Enable check for tests like [ "$var" ], which are best written [ -n "$var" ].
-enable=avoid-nullary-conditions