feat: add spacebar hold for 2x speed in player with proper listener c…

[i-amansharma07]

What was missing

The player had no way to temporarily boost speed by holding a key. This PR adds the spacebar hold gesture which is a common pattern in video players (e.g. YouTube).

What was added

• Holding space kicks the playback rate to 2x
• Releasing space restores the previous playback rate (not hardcoded to 1x — respects whatever rate the user was already at)
• If the video was paused when the hold started, it auto-plays during the hold
• A quick tap of space still toggles play/pause as expected

Action	Result
Hold space	Playback jumps to 2x
Release space	Restores previous rate
Tap space while playing	Pauses
Tap space while paused	Plays
Hold space while paused	Auto-plays at 2x, restores on release

Cleanup Logic

Both listeners are correctly registered and removed:

keydown is registered with { capture: true } so it fires before Video.js
internal handlers can intercept it. The removal must mirror the same flag —
without it, the browser treats capture and non-capture registrations as distinct
listeners and the removal becomes a no-op, leaking the listener on every unmount.

keyup removal was simply absent, causing a new duplicate listener to stack up
on every re-render triggered by player state changes.

Checklist before requesting a review

• [✅] I have performed a self-review of my code
• [✅] I assure there is no similar/duplicate pull request regarding same issue