fix: align sidebar footer actions

[Sure-Will]

Description

Align the Theme, Language, and Sign Out actions in the expanded sidebar footer.

The Theme toggle wrapped its icons in a container, so the shared button selector for direct SVG children did not apply the same horizontal padding used by the other actions. The Sign Out action also used a larger gap. This change gives the Theme toggle an explicit 12 px horizontal inset, uses a 16 px icon container, and applies the same 8 px gap to all three actions.

Related Issue

N/A (small, obvious UI fix)

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring (no functional changes)
• Performance improvement
• Test coverage improvement

How Has This Been Tested?

• Tested locally with Docker
• Tested locally with development setup
• Added new unit tests
• Existing frontend tests pass
• Manual testing performed

Test Details:

• npm run test: 23 test files and 141 tests passed.
• npm run lint: completed with no errors. The seven existing warnings are outside the changed files.
• npm run build: production build and TypeScript checks passed.
• Docker runtime verification confirmed that the API on port 5055 is healthy and the UI on port 8502 is available.
• Browser verification at 1280 x 720 confirmed that all three expanded footer actions use a 12 px left inset, an 8 px gap, icon x-position 25, and label x-position 49. Collapsed footer icons remained centered.

Test Files  23 passed (23)
Tests       141 passed (141)

Lint        0 errors, 7 existing warnings
Build       Compiled successfully; TypeScript completed
Docker      API healthy; UI available

Design Alignment

Which design principles does this PR support?

• Privacy First
• Simplicity Over Features
• API-First Architecture
• Multi-Provider Flexibility
• Extensibility Through Standards
• Async-First for Performance

Explanation:

This is a focused consistency fix for existing controls. It adds no new behavior or configuration.

Checklist

Code Quality

• My code follows PEP 8 style guidelines (Python)
• My code follows TypeScript best practices (Frontend)
• I have added type hints to my code (Python)
• I have added JSDoc comments where appropriate (TypeScript)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings or errors

Testing

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I ran frontend linting with npm run lint
• I ran TypeScript checking as part of npm run build

Documentation

• I have updated the relevant documentation in /docs (not applicable)
• I have added/updated docstrings for new/modified functions (not applicable)
• I have updated the API documentation (not applicable)
• I have added comments to complex logic (not applicable)

Database Changes

• I have created migration scripts for any database schema changes (not applicable)
• Migration includes both up and down scripts (not applicable)
• Migration has been tested locally (not applicable)

Breaking Changes

• This PR includes breaking changes
• I have documented the migration path for users (not applicable)
• I have updated MIGRATION.md (not applicable)

Screenshots

Before

The Theme icon is shifted 4 px to the right of the Language and Sign Out icons.

After

The three icons now share the same horizontal position and spacing.

Additional Context

This is a three-file frontend-only change with no dependency, API, database, or documentation impact.

Pre-Submission Verification

• I have read CONTRIBUTING.md
• I have read VISION.md
• This is a small, obvious fix that does not require an approved Issue
• I have not included unrelated changes in this PR
• My PR title follows conventional commits format

[cubic-dev-ai]

All reported issues were addressed across 3 files

<sub>Reply with feedback, questions, or to request a fix.

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[cubic-dev-ai]

All reported issues were addressed across 1 file (changes from recent commits).

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>