diff --git a/engineering/ide/.vscode/README.md b/engineering/ide/.vscode/README.md
index ebc45af..67b7fce 100755
--- a/engineering/ide/.vscode/README.md
+++ b/engineering/ide/.vscode/README.md
@@ -34,6 +34,26 @@ descriptions of the information:
    used in any rails project. (More
    Information)[https://rahul-arora.medium.com/debugging-ruby-on-rails-server-in-vs-code-819b45113e78]
 
+## Settings Sync — extensions are dotfiles-owned (do this on every machine)
+
+**This repo is the single source of truth for extensions** — the `extensions*.txt` lists,
+installed by `onboarding_bin/vscode-install-extensions-*.sh`. VS Code **Settings Sync is NOT**.
+
+Settings Sync will silently add / remove / enable / disable extensions to match another machine
+or an older cloud snapshot. On **2026-08-11** it uninstalled `dbaeumer.vscode-eslint` and
+`esbenp.prettier-vscode` here, silently breaking lint and format-on-save. To keep dotfiles
+authoritative:
+
+1. **Turn the Extensions resource OFF in Settings Sync — on every machine.** There is no
+   `settings.json` key for this; it is UI-only:
+   Command Palette → **Settings Sync: Configure…** → uncheck **Extensions**.
+2. `settings.json` → `settingsSync.ignoredExtensions` lists the core dev tools (eslint, prettier,
+   stylelint, shell-format) as a per-extension safety net — no wildcard is supported, so it can
+   only protect named extensions, which is why step 1 is the real fix.
+
+Settings / Keybindings / Snippets are also symlinked from this repo, so consider turning those
+Sync resources off too if you want dotfiles fully authoritative.
+
 ## Extensions
 
 *Needs to be cross checked with extensions_base.txt and updated for 2023*
diff --git a/engineering/ide/.vscode/extensions.txt b/engineering/ide/.vscode/extensions.txt
index de67b3a..f2d357b 100755
--- a/engineering/ide/.vscode/extensions.txt
+++ b/engineering/ide/.vscode/extensions.txt
@@ -15,9 +15,7 @@ cpylua.language-postcss
 davidanson.vscode-markdownlint
 dbaeumer.vscode-eslint
 deque-systems.vscode-axe-linter
-dsznajder.es7-react-js-snippets
 eamodio.gitlens
-equimper.react-native-react-redux
 esbenp.prettier-vscode
 exiasr.hadolint
 firsttris.vscode-jest-runner
@@ -26,25 +24,16 @@ foxundermoon.shell-format
 github.codespaces
 github.vscode-github-actions
 github.vscode-pull-request-github
-gluca.log-view-l4n
-h501cloud.html-email-preview
 htmlhint.vscode-htmlhint
 ibm.output-colorizer
 jmfirth.vsc-space-block-jumper
-jmrog.vscode-nuget-package-manager
-johnpapa.angular-essentials
-johnpapa.angular2
-johnpapa.vscode-peacock
-johnpapa.winteriscoming
 koichisasada.vscode-rdbg
 l13rary.l13-diff
 letrieu.expand-region
 manuelpuyol.erb-linter
 mengrbatinov.json-snippet-to-md-documentation
-mikestead.dotenv
 mongodb.mongodb-vscode
 moshfeu.diff-merge
-ms-azuretools.vscode-docker
 ms-dotnettools.csdevkit
 ms-dotnettools.csharp
 ms-dotnettools.dotnet-maui
@@ -57,7 +46,6 @@ ms-python.vscode-pylance
 ms-vscode-remote.remote-containers
 ms-vscode-remote.remote-ssh
 ms-vscode-remote.remote-ssh-edit
-ms-vscode-remote.remote-wsl
 ms-vscode-remote.vscode-remote-extensionpack
 ms-vscode.powershell
 ms-vscode.remote-explorer
@@ -66,18 +54,15 @@ ms-vscode.vs-keybindings
 ms-vscode.vscode-speech
 ms-vscode.wordcount
 ms-vsliveshare.vsliveshare
-nrwl.angular-console
 ofhumanbondage.react-proptypes-intellisense
 orta.vscode-jest
 ortoni.ortoni
-pkief.angular-component-extractor
 pkief.material-icon-theme
 pranaygp.vscode-css-peek
 prisma.prisma
 redhat.vscode-yaml
 richie5um2.vscode-sort-json
 ritwickdey.liveserver
-runem.lit-plugin
 ryu1kn.partial-diff
 saoudrizwan.claude-dev
 shopify.ruby-lsp
@@ -88,7 +73,6 @@ streetsidesoftware.code-spell-checker
 stylelint.vscode-stylelint
 thinker.sort-json
 timonwong.shellcheck
-tlevesque2.duplicate-finder
 tomoki1207.pdf
 tyriar.sort-lines
 usernamehw.errorlens
diff --git a/engineering/ide/.vscode/extensions_base.txt b/engineering/ide/.vscode/extensions_base.txt
index 29bd867..2ba5709 100644
--- a/engineering/ide/.vscode/extensions_base.txt
+++ b/engineering/ide/.vscode/extensions_base.txt
@@ -8,16 +8,13 @@ eamodio.gitlens
 esbenp.prettier-vscode
 foxundermoon.shell-format
 GitHub.codespaces
-GitHub.copilot
 github.vscode-github-actions
 GitHub.vscode-pull-request-github
 HTMLHint.vscode-htmlhint
 jmfirth.vsc-space-block-jumper
 L13RARY.l13-diff
 letrieu.expand-region
-mikestead.dotenv
 moshfeu.diff-merge
-ms-azuretools.vscode-docker
 ms-dotnettools.vscode-dotnet-runtime
 ms-playwright.playwright
 ms-vscode-remote.remote-containers
@@ -27,7 +24,6 @@ ms-vscode-remote.vscode-remote-extensionpack
 ms-vscode.remote-explorer
 ms-vscode.remote-server
 ms-vscode.vs-keybindings
-PKief.material-icon-theme
 pranaygp.vscode-css-peek
 redhat.vscode-yaml
 richie5um2.vscode-sort-json
diff --git a/engineering/ide/.vscode/extensions_devops.txt b/engineering/ide/.vscode/extensions_devops.txt
index dc66690..e1e4cd9 100644
--- a/engineering/ide/.vscode/extensions_devops.txt
+++ b/engineering/ide/.vscode/extensions_devops.txt
@@ -4,11 +4,9 @@ formulahendry.github-actions
 henriiik.docker-linter
 KnisterPeter.vscode-github
 me-dutour-mathieu.vscode-github-actions
-ms-azuretools.vscode-docker
 ms-kubernetes-tools.vscode-aks-tools
 ms-kubernetes-tools.vscode-kubernetes-tools
 ms-vscode.remote-explorer
 ms-vscode-remote.remote-ssh
 ms-vscode-remote.remote-ssh-edit
-ms-vscode-remote.remote-wsl
 MS-vsliveshare.vsliveshare
diff --git a/engineering/ide/.vscode/extensions_react.txt b/engineering/ide/.vscode/extensions_react.txt
index f1a3896..7c9b5f9 100644
--- a/engineering/ide/.vscode/extensions_react.txt
+++ b/engineering/ide/.vscode/extensions_react.txt
@@ -1,4 +1,2 @@
 christian-kohler.npm-intellisense
-dsznajder.es7-react-js-snippets
-EQuimper.react-native-react-redux
 wix.vscode-import-cost
diff --git a/engineering/ide/.vscode/settings.json b/engineering/ide/.vscode/settings.json
index e4c4e01..b2115ad 100755
--- a/engineering/ide/.vscode/settings.json
+++ b/engineering/ide/.vscode/settings.json
@@ -141,9 +141,7 @@
   },
   "yaml.format.singleQuote": false,
   "yaml.format.proseWrap": "never",
-  "yaml.schemaStore.enable": true,
-  "yaml.trace.server": "verbose",
-  "[yaml]": {
+  "yaml.schemaStore.enable": true,  "[yaml]": {
     "editor.defaultFormatter": "redhat.vscode-yaml",
   },
   "accessibility.signals.terminalBell": {
@@ -177,7 +175,7 @@
     "research",
     "bugfix",
   ],
-  "atlascode.jira.startWorkBranchTemplate.customTemplate": "{{{prefix}}}/{{{issueKey}}}-{{{summary}}}",
+  "atlascode.jira.startWorkBranchTemplate.customTemplate": "{{{prefix}}}{{{issueKey}}}-{{{summary}}}",
   "atlascode.jira.statusbar.showUser": false,
   "atlascode.jira.todoIssues.triggers": [
     "BUG:",
@@ -201,9 +199,7 @@
   "vscode-yaml-sort.extensions": ["yaml", "yml"],
   "editor.autoClosingQuotes": "languageDefined",
   "editor.autoIndent": "advanced",
-  "editor.autoSurround": "languageDefined",
-  "atlascode.outputLevel": "debug",
-  "autoimport.filesToScan": "**/*.{js,jsx,ts,tsx,css,scss}",
+  "editor.autoSurround": "languageDefined",  "autoimport.filesToScan": "**/*.{js,jsx,ts,tsx,css,scss}",
   "autoimport.showNotifications": true,
   "breadcrumbs.enabled": true,
   "codespaces.accountProvider": "GitHub",
@@ -515,6 +511,7 @@
     "Newtonsoft",
     "NEXTAUTH",
     "nextjs",
+    "nivo",
     "nodelist",
     "noninteractive",
     "noopener",
@@ -710,11 +707,9 @@
   },
   "debug.openExplorerOnEnd": false,
   "debug.terminal.clearBeforeReusing": true,
-  "debug.toolBarLocation": "docked",
-  "dev.containers.logLevel": "trace",
-  "diffEditor.codeLens": true,
+  "debug.toolBarLocation": "docked",  "diffEditor.codeLens": true,
   "diffEditor.experimental.showMoves": false,
-  "diffEditor.ignoreTrimWhitespace": false,
+  "diffEditor.ignoreTrimWhitespace": true,
   "diffEditor.useInlineViewWhenSpaceIsLimited": false,
   "docker.images.sortBy": "CreatedTime",
   "dotfiles.installCommand": "install",
@@ -745,7 +740,7 @@
   "editor.guides.indentation": true,
   "editor.hover.delay": 200,
   "editor.inlineCompletionsAccessibilityVerbose": true,
-  "editor.largeFileOptimizations": false,
+  "editor.largeFileOptimizations": true,
   "editor.minimap.enabled": false,
   "editor.quickSuggestions": {
     "comments": "off",
@@ -845,6 +840,8 @@
     "**/dist/**": true,
     "**/.git/**": true,
     "**/storybook-static/**": true,
+    "**/coverage/**": true,
+    "**/build/**": true,
   },
   "gistpad.playgrounds.showConsole": true,
   "gistpad.playgrounds.stylesheetLanguage": "scss",
@@ -940,14 +937,10 @@
   "gitlens.views.repositories.files.layout": "list",
   "gitlens.views.repositories.showIncomingActivity": false,
   "gitlens.views.search.enabled": false,
-  "gitlens.views.searchAndCompare.files.layout": "tree",
-  "grammarly.debug": true,
-  "hadolint.hadolintPath": "/opt/homebrew/bin/hadolint",
+  "gitlens.views.searchAndCompare.files.layout": "tree",  "hadolint.hadolintPath": "/opt/homebrew/bin/hadolint",
   "html.format.enable": true,
   "html.format.extraLiners": "none",
-  "html.format.templating": true,
-  "html.trace.server": "messages",
-  "htmlhint.documentSelector": ["htm", "html"],
+  "html.format.templating": true,  "htmlhint.documentSelector": ["htm", "html"],
   "javascript.preferences.importModuleSpecifier": "non-relative",
   "keyboard.layout": "us",
   "l13Diff.confirmCopy": false,
@@ -961,23 +954,17 @@
   "liveServer.settings.donotVerifyTags": true,
   "liveServer.settings.wait": 500,
   "liveshare.allowGuestDebugControl": true,
-  "liveshare.allowGuestTaskControl": true,
-  "liveshare.diagnosticLogging": true,
-  "liveshare.presence": true,
+  "liveshare.allowGuestTaskControl": true,  "liveshare.presence": true,
   "markdown.experimental.updateLinksOnPaste": true,
   "markdown.extension.completion.enabled": true,
   "markdown.extension.print.theme": "dark",
-  "markdown.preview.fontSize": 16,
-  "markdown.server.log": "debug",
-  "markdown.validate.unusedLinkDefinitions.enabled": "warning",
+  "markdown.preview.fontSize": 16,  "markdown.validate.unusedLinkDefinitions.enabled": "warning",
   "markdownlint.run": "onSave",
   "merge-conflict.autoNavigateNextConflict.enabled": true,
   "npm.packageManager": "npm",
   "path-intellisense.autoSlashAfterDirectory": true,
   "playwright.reuseBrowser": false,
-  "playwright.showTrace": false,
-  "prettier.enableDebugLogs": true,
-  "prettier.proseWrap": "never",
+  "playwright.showTrace": false,  "prettier.proseWrap": "never",
   "prettier.singleQuote": true,
   // "prettier.requireConfig": true,
   "prettier.useEditorConfig": false,
@@ -1019,7 +1006,18 @@
   "search.useIgnoreFiles": false,
   "security.promptForLocalFileProtocolHandling": false,
   "security.workspace.trust.untrustedFiles": "open",
-  "settingsSync.ignoredExtensions": ["ms-vscode-remote.remote-containers"],
+  // Extensions are owned by this repo (extensions*.txt), NOT Settings Sync.
+  // Sync silently uninstalled eslint + prettier on 2026-08-11; these entries are a
+  // per-extension safety net (no wildcard is supported). The full fix is to turn the
+  // Extensions resource OFF in "Settings Sync: Configure..." on every machine — see
+  // engineering/ide/.vscode/README.md § Settings Sync.
+  "settingsSync.ignoredExtensions": [
+    "dbaeumer.vscode-eslint",
+    "esbenp.prettier-vscode",
+    "foxundermoon.shell-format",
+    "ms-vscode-remote.remote-containers",
+    "stylelint.vscode-stylelint",
+  ],
   "shellcheck.enable": true,
   "shellcheck.enableQuickFix": true,
   "shellcheck.ignoreFileSchemes": ["git", "gitfs"],
@@ -1172,6 +1170,14 @@
   "terminal.integrated.wordSeparators": "()[]{}',\"`─‘’|",
   "typescript.suggest.completeFunctionCalls": true,
   "typescript.validate.enable": true,
+  // macOS: watch parent directories via FSEvents instead of one kqueue fd per
+  // file. Collapses tsserver's ~1600 open fds (dominated by generated OpenAPI
+  // model files) to a handful of dir watchers — the real fd consumer per window.
+  "typescript.tsserver.watchOptions": {
+    "watchFile": "useFsEventsOnParentDirectory",
+    "watchDirectory": "useFsEvents",
+    "fallbackPolling": "dynamicPriority",
+  },
   "vsintellicode.modify.editor.suggestSelection": "automaticallyOverrodeDefaultValue",
   "window.newWindowDimensions": "maximized",
   "window.restoreWindows": "all",
@@ -1196,17 +1202,16 @@
   "workbench.startupEditor": "welcomePage",
   "workbench.tree.indent": 4,
   "workbench.view.alwaysShowHeaderActions": true,
-  "window.confirmSaveUntitledWorkspace": false,
-  "eslint.debug": true,
-  "terminal.integrated.env.osx": {},
+  "window.confirmSaveUntitledWorkspace": false,  "terminal.integrated.env.osx": {},
   "gitlens.views.scm.grouped.views": {
-    "commits": false,
+    "commits": true,
     "branches": false,
     "remotes": true,
     "stashes": false,
     "tags": false,
     "worktrees": false,
     "contributors": false,
+    "fileHistory": false,
     "repositories": true,
     "searchAndCompare": true,
     "launchpad": false,
@@ -1215,7 +1220,7 @@
     "all": true,
   },
   "chat.editing.alwaysSaveWithGeneratedChanges": true,
-  "scm.diffDecorationsIgnoreTrimWhitespace": "true",
+  "scm.diffDecorationsIgnoreTrimWhitespace": true,
   "l13Diff.ignoreTrimWhitespace": "on",
   "gitlens.blame.ignoreWhitespace": true,
   "gitlens.advanced.fileHistoryShowAllBranches": true,
@@ -1224,9 +1229,7 @@
   "application.shellEnvironmentResolutionTimeout": 20,
   "geminicodeassist.project": "retail-success-449215",
   "githubPullRequests.pushBranch": "always",
-  "git.openRepositoryInParentFolders": "prompt",
-  "diffEditor.maxComputationTime": 0,
-  "dotenv.enableAutocloaking": false,
+  "git.openRepositoryInParentFolders": "always",  "dotenv.enableAutocloaking": false,
   "cSpell.checkVSCodeSystemFiles": true,
   "cSpell.allowCompoundWords": true,
   "cSpell.logLevel": "Warning",
@@ -1276,8 +1279,19 @@
     "npm run lint:errors-only": true,
     "npx vitest": true,
   },
-  "chat.viewSessions.orientation": "stacked",
   "claudeCode.preferredLocation": "panel",
   "terminal.integrated.initialHint": false,
   "chat.useClaudeHooks": true,
+  "yaml.disableSchemaDetection": [
+    "**/.github/workflows/*.yml",
+    "**/.github/workflows/*.yaml",
+    "**/.gitea/workflows/*.yml",
+    "**/.gitea/workflows/*.yaml",
+    "**/.forgejo/workflows/*.yml",
+    "**/.forgejo/workflows/*.yaml",
+    "azure-pipelines.yml",
+    "azure-pipelines.yaml",
+  ],
+  "diffEditor.hideUnchangedRegions.enabled": true,
+  "chat.viewSessions.orientation": "stacked",
 }