feat(clean): report size of removed files

[baszalmstra]

Description

pixi clean is now a tiny bit more rewarding: it tells you how much disk space you just liberated. Because "removed your environments" hits different when followed by "(4.2 GiB)".

The recursive deletion now sums file sizes as it goes. Each folder gets its own Removed <path> (<size>) line and the run ends with a bold Removed <total> summary.

Works for pixi clean, pixi clean --environment, pixi clean cache, and friends.

How Has This Been Tested?

• cargo check -p pixi_cli
• cargo clippy -p pixi_cli --all-targets -- -D warnings
• cargo fmt --all -- --check
• Manual: ran pixi clean and pixi clean cache on a real workspace,
  watched the spinner spin and the bytes add up.

AI Disclosure

• This PR contains AI-generated content.
  • I have tested any AI-generated content in my PR.
  • I take responsibility for any AI-generated content in my PR.

Tools: Claude

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas

[baszalmstra]

@ruben-arts This is ready

[ruben-arts]

I did a similar test as in this PR: #5218

➜ hyperfine -p 'pixi exec -s pytorch python --version' "PIXI_CACHE_DIR=/tmp/pixi_cache pi
xi clean cache --yes" "PIXI_CACHE_DIR=/tmp/pixi_cache pixi-6053 clean cache --yes" -w 1
Benchmark 1: PIXI_CACHE_DIR=/tmp/pixi_cache pixi clean cache --yes
  Time (mean ± σ):      3.296 s ±  0.051 s    [User: 0.025 s, System: 2.539 s]
  Range (min … max):    3.212 s …  3.373 s    10 runs
 
Benchmark 2: PIXI_CACHE_DIR=/tmp/pixi_cache pixi-6053 clean cache --yes
  Time (mean ± σ):      3.575 s ±  0.064 s    [User: 0.046 s, System: 2.796 s]
  Range (min … max):    3.469 s …  3.688 s    10 runs
 
Summary
  PIXI_CACHE_DIR=/tmp/pixi_cache pixi clean cache --yes ran
    1.08 ± 0.03 times faster than PIXI_CACHE_DIR=/tmp/pixi_cache pixi-6053 clean cache --yes

It's a non significant slowdown but I'm not sure what the change would be if the cache was even larger. Do you think the UX improvement is more important than speed?

[baszalmstra]

I can deep dive what is causing that but I assume the extra stat calls.

I do think showing how much is actually removed (barring links) is much better yes!

[wolfv]

@ruben-arts just to be sure, did you compile in release mode?

[ruben-arts]

@ruben-arts just to be sure, did you compile in release mode?

I did, pixi = main pixi-6053 is this PR.