fix: refresh stale default Anthropic model names

[kapelame]

Description

Three places in the codebase hard-code stale Anthropic model ids as fallback defaults when the user hasn't supplied one. As of 2026 Anthropic ships Opus 4.7 and Sonnet 4.6, and the modern naming convention drops the date suffix (the repo's own docs/reference/teamsbotconfig.md already uses claude-sonnet-4-6, so this aligns the fallbacks with the docs).

These are pure fallback defaults — MODEL_NAME env var and the wizard's Model Name field still take precedence, so behavior is unchanged for anyone who has already configured a model.

Related Issue

None.

Changes

File	Was	Now
deployer/config.py:75	claude-opus-4-6	claude-opus-4-7
deployer/windows_setup.py:1556	claude-opus-4-6	claude-opus-4-7
desktop/renderer/src/views/SetupWizard.vue:222	claude-sonnet-4-20250514	claude-sonnet-4-6

Total diff: 3 files / +3 / -4 (one extra - is from Prettier auto-collapsing a two-line ternary once the new string was short enough to fit on one line).

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature
• Breaking change
• Documentation update
• CI/CD or build configuration change
• Refactoring (no functional changes)

Testing

• Renderer tests pass locally (cd desktop/renderer && npm run test) — 8 files / 139 tests, all green
• Python syntax + DEFAULT_CONFIG load check — python3 -m py_compile clean on both .py files; imported DEFAULT_CONFIG and asserted model_name == "claude-opus-4-7" ✓
• Prettier on touched Vue file — clean after auto-format
• ESLint on touched Vue file — 3 pre-existing warnings (lines 57, 228, 281), none on the changed line 222
• Repo-wide grep confirms no remaining references to claude-opus-4-6 or claude-sonnet-4-20250514
• Build succeeds (cd desktop && npm run build) — not run locally (no Windows toolchain on this dev machine); CI pr-build.yml will gate
• Manual reasoning: change is pure string-literal substitution in default-fallback positions; user-supplied values still win

Checklist

• My code follows the coding guidelines of this project
• I have performed a self-review of my code
• No new comments needed — value swap only
• Documentation already uses the modern naming convention (claude-sonnet-4-6); this PR aligns code with docs
• No new warnings introduced (Prettier and ESLint diffs are clean on the changed line)
• No new tests added — this is a configuration default value swap with no logic change
• Existing tests pass locally with the change applied