Fix weird spacing on Start Session button in empty console

[dhruvisompura]

This is a non-fork PR applying the commits from #14381 by @PGupta-Git because of the problems outlined in #14155.

Fixes #14155

Description

Fixes the weird spacing around the Start Session button in the Console when no session is running.

Root Cause

This was introduced in #12795 which replaced PositronButton (a <div role="button"> with zero browser-default padding) with the Button component (a native <button> element).

Native <button> elements have browser UA stylesheet default padding (1px 6px). When used inline within a text sentence — "There is no session running. Use [Start Session] to start one." — this padding creates unwanted vertical and horizontal whitespace around the button text, making it look like a hyperlink with extra internal spacing.

Fix

Added two CSS properties to the .link rule in emptyConsole.css:

padding: 0;           /* remove browser default button padding */
vertical-align: baseline; /* keep button text aligned with surrounding text */

This resets the UA default padding for the button in this specific inline-text context only (scoped to .empty-console .title .link), without affecting the Button component globally.

Release Notes

New Features

• N/A

Bug Fixes

• Fixes weird spacing with "Start Session" button in an empty console (console UI: "no session running" button has weird spacing #14155)

Validation Steps

@:console
@:sessions

• Existing Vitest unit tests in emptyConsole.vitest.tsx continue to pass — they verify the text content and click behavior, which are unaffected.
• Visually: open a new Positron window before any session is started and confirm the "Start Session" button text sits flush with the surrounding sentence text.

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical @:console @:sessions

^{readme  valid tags}

[github-actions]

PETE's assessment 🧪

Verdict: 🟡 Not applicable -- the change is a 2-line CSS tweak (padding: 0; vertical-align: baseline;) that adjusts visual spacing only, with no testable behavior change.

What changed

• Added padding: 0 and vertical-align: baseline to the .empty-console .title .link rule in emptyConsole.css to reset the native <button> UA padding so the inline "Start Session" button sits flush with surrounding text. No TypeScript, markup, or logic touched.

Tests in this PR

• Unit (Vitest/Mocha) ✅ (not applicable -- CSS-only; existing emptyConsole.vitest.tsx still covers render + click)
• Extension host ✅ (not applicable)
• E2E (Playwright) ✅ (not applicable -- visual spacing, not a workflow)

Existing coverage

src/vs/workbench/contrib/positronConsole/test/browser/emptyConsole.vitest.tsx already asserts the empty-state message renders, the Start Session button renders, and pressing it executes startNewConsoleSession. These behaviors are unchanged by a CSS padding/alignment reset, so they remain valid. Pixel-level spacing isn't expressible as a Vitest/RTL assertion and doesn't justify an e2e test for a cosmetic fix.

Suggested additions

None.

---

PETE (Positron Extreme Test Experiment) - LLM-based test-coverage advisor, in pilot. Triggers on PR open and on /recheck-tests comments. Wrong verdict? Comment /recheck-tests (or /rePETE) on this PR to re-run. Please share feedback on how PETE performed here.