Release v1.4.0: the notes, and the Welcome page says what the site says

[ndemianc]

Everything v1.4.0 needs before it is tagged. Two commits:

1. fix(copy): the app stops calling itself hackable. That word was in five places a user reads: the Welcome walkthrough (now the site's line, "The AI code editor that keeps you in control"), the Customize panel's section, and the customization extension's name, description and settings title (now LevelCode Customization). The extension's id and settings keys are unchanged, so nothing that refers to them breaks.
2. docs: RELEASE-NOTES.md for v1.4.0. Written against v1.3.1, from scripts/draft-release-notes.mjs 1.4.0 for the facts (range, PRs, test counts) and the code for every claim. The highlights:
   • Open VSX extensions install verified (Verify Open VSX extension signatures — installs and extension updates work again #103)
   • the agent draws diagrams (feat(diagrams): the agent draws in the chat — render_diagram, phase 1 of the Rich Diagrams spec #104)
   • Gemini 4 Argon sized, with room for reasoning models (feat(ai): Gemini 4 Argon, sized as it is — its window, its reasoning, and room to think #108)
   • Also fixed: fix(agent): a markdown "Done:" line ends the run — the finished answer was being nudged #102 and the long-command fixes
   • Not in this release: the browser edition is in the source but not hosted; diagrams not yet drawn by every live model; Argon's reasoning not carried between steps; the Sessions panel still does not search; no Windows or Linux build.

Checked before tagging

Three changes in this release were never run in the real desktop editor, by their own PRs' accounts: #105's rework of the agent's file reads and writes, #104's diagrams and #108's Argon handling. Both runs below used the dev build (vscode/.build/electron) as a throwaway instance, with develop's extension (179eb03) and a local stand-in model:

• scripts/diagram-editor-check.js: 19 / 19. The chat, an agent turn, a diagram painted in the webview in the theme, Full size, a linked box opening router.js at line 4, and the session on disk.
• A release smoke run (a scratch script on the same harness, not committed): 13 / 13, with the model set to google/gemini-4-argon:
  • write_file lands on disk and goes under review ("1 file changed").
  • run_command waits for approval, then runs in the real shell, and its output (hello.txt, router.js) reaches the model.
  • The answer is shown, and the session is saved.
  • Undo takes the file back off the disk.
  • Every agent turn asked for reasoning: { effort: "medium" } and max_tokens: 32768.
  • Nothing threw.
• Gate: scripts/test-extensions.sh on this branch: 126 files, macOS, Node 24.

Not run: a live model in the editor, the packaged app (CI builds and smoke-tests that), and the Linux suite run (Docker was unavailable here; the release workflow's test job runs on Linux).

After merging (from docs/RELEASING.md §7)

1. Pull develop, then git tag v1.4.0 && git push --tags. CI builds both arches and opens a draft release with the unsigned zips.
2. Sign and notarize locally with make-dmg.sh for arm64 and x64, then upload the dmgs and update zips and drop the unsigned zips.
3. gh release edit v1.4.0 --draft=false --notes-file RELEASE-NOTES.md. Run it from a checkout that has this PR merged and pulled; v1.3.1 went out with v1.3.0's notes. Afterwards, gh release view v1.4.0 --json body --jq '.body[0:40]' should start with # LevelCode v1.4.0.

[Copilot]

🟡 Changes recommended

Signature-verification guidance needs correction so users understand upgrade protection and key-rotation failures.

2 open findings

• Clarify upgrade caveat for users with signature verification disabled · New
• Avoid promising advance warning for packages signed with the new key · New

What changed in this PR

Prepares v1.4.0 release notes and aligns desktop onboarding and customization labels with the site's wording.

Changes:

• Documents release highlights, fixes, testing, and known limitations.
• Updates user-facing copy without changing extension IDs, settings keys, or commands.

File	Description
RELEASE-NOTES.md	Replaces previous notes with v1.4.0 release details.
extensions/​levelcode-hackability/​package.json	Renames display labels to LevelCode Customization.
extensions/​levelcode-ai/​package.json	Updates the Welcome walkthrough description.
extensions/​levelcode-ai/​customize.js	Renames the panel section to Customization.

🧠 Review effort: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.