fix: honor backpressure in decompression interceptor

[mcollina]

I made a mess of the original GHSA fix by treating a stream backpressure bug as a response-size policy decision.

A 64 MiB limit answers a different question: how large a decoded response an application is willing to accept. It also rejects legitimate responses that can be consumed safely as streams. The correct fix is to honor the stream contract: stop pulling decoded output when the consumer pauses, propagate writable pressure from the decoder back to the transport, keep those pause reasons independent across retries, and wait to signal completion until the consumer resumes.

maxSize still exists as an opt-in per-stage circuit breaker. It now defaults to 0, leaving size policy to applications while backpressure keeps buffering tied to consumer demand.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 92.63566% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.48%. Comparing base (fb3d786) to head (409b1f4).
⚠️ Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/interceptor/decompress.js	91.66%	19 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5829      +/-   ##
==========================================
- Coverage   93.50%   93.48%   -0.03%     
==========================================
  Files         110      110              
  Lines       39557    39755     +198     
==========================================
+ Hits        36987    37163     +176     
- Misses       2570     2592      +22     

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[github-actions]

The backport to v7.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-v7.x v7.x
# Navigate to the new working tree
cd .worktrees/backport-v7.x
# Create a new branch
git switch --create backport-5829-to-v7.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 19901d8b73cb46a48e817dab4afce790f37fd2c1
# Push it to GitHub
git push --set-upstream origin backport-5829-to-v7.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-v7.x

Then, create a pull request where the base branch is v7.x and the compare/head branch is backport-5829-to-v7.x.