stream: align Readable.toWeb termination with eos

[ikeyan]

This aligns Readable.toWeb(stream) termination handling with
eos(stream, { writable: false }).

Changes:

• add regression tests for half-open duplex termination
• add regression coverage for adapter creation before and after
  end(), destroy(), and destroy(error)
• preserve terminated Readable adapter state, including closed/error
  state and byte stream type, regardless of when the adapter is created
• let Readable.toWeb() reuse eos() immediate completion handling
  for already-terminated streams
• add regression coverage for the synchronous internal EOS callback
  path, including listener cleanup and BYOB termination

Tests:

• make lint
• ./configure && make -j4 test

[nodejs-github-bot]

Review requested:

• @nodejs/streams

[codecov]

Codecov Report

❌ Patch coverage is 99.53052% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.64%. Comparing base (8199f9c) to head (cbe1987).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/streams/end-of-stream.js	99.31%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62394      +/-   ##
==========================================
- Coverage   89.69%   89.64%   -0.06%     
==========================================
  Files         676      674       -2     
  Lines      206693   205684    -1009     
  Branches    39577    39443     -134     
==========================================
- Hits       185402   184384    -1018     
- Misses      13435    13535     +100     
+ Partials     7856     7765      -91     

Files with missing lines	Coverage Δ
lib/internal/webstreams/adapters.js	86.43% <100.00%> (-0.02%)	⬇️
lib/internal/streams/end-of-stream.js	98.28% <99.31%> (+0.85%)	⬆️

... and 133 files with indirect coverage changes

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