feat(projects): add "New project" creation (mkdir + git init)

[writingdeveloper]

Summary

Adds a "+ New project" button to the projects toolbar that creates a new project folder under a scan root and git inits it, then opens it in a terminal with the active agent and refreshes the deck.

git init is not cosmetic: the scanner only surfaces folders containing a .git directory, so initialising the repo is what makes the new project appear in the deck.

What's new

• shared/projectName.ts — pure, shared name validation reused by the main process (authoritative) and the renderer (instant feedback). Allows spaces/dots/hyphens, rejects illegal/reserved/too-long names, returns a trimmed canonical name.
• main/createProject.ts — mkdir + git init, guarded by isAllowedPath (the same guard used by open/openFolder, so a compromised renderer can't mkdir anywhere). Deps injectable for tests.
• IPC project:create + preload bridge + global.d.ts type.
• renderer/newProjectModal.ts — small modal: scan-root picker with a browse fallback (a freshly picked dir registers as a scan root), live path preview, inline validation errors. Toolbar button + localized label.
• i18n ko/en/ja/zh, modal styles, QA harness modal scene.

Decisions

• Scope: minimal (empty folder + git init) — fits DevDeck's "command deck" identity; no template/scaffold system.
• Location: created under a scan root so it auto-appears on the next scan (browse fallback registers the picked dir as a root).
• After create: opens in a terminal with the active agent (claude/codex).

Test plan

• tsc + renderer bundle clean
• Unit tests: 162 passing (+16 — projectName 10, createProject 6), incl. guard/validation/dup/git-unavailable paths
• Playwright QA harness: 0 console / 0 page errors across ko/en/ja/zh; modal default + validation-error states captured
• Real git init path verified end-to-end in a temp dir (gitInitialized: true, .git created)

🤖 Generated with Claude Code

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Resolve parent symlinks before mkdir

When a configured scan root contains a symlink to another directory, this guard accepts a renderer-supplied parent like <root>/link because isAllowedPath only checks the resolved string prefix, but mkdirSync(join(parent, name)) then follows the symlink and creates the project outside the allowed roots. Since project:create is exposed to the renderer and this path is used for filesystem writes, resolve/realpath the parent or reject symlink parents before creating the directory.

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