feat: add support for libp2p pnet

[aschmahmann]

No description provided.

[Copilot]

Pull request overview

This PR adds support for libp2p private networks (pnet) by implementing swarm key functionality. The key change enables users to specify a private network swarm key file via a --pnet flag, which is then used to configure libp2p hosts for secure, isolated network operations.

• Introduces pnet swarm key loading and context management
• Updates all libp2p host creation points to accept and use context-based pnet configuration
• Adds comprehensive test coverage for pnet functionality

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
main.go	Adds global --pnet flag and Before hook to load swarm key into context; updates GetBitswapCID call signature
lib/pnet.go	Implements pnet PSK loading from file and context storage/retrieval functions
lib/pnet_test.go	Tests pnet PSK loading, validation, and network isolation behavior
lib/libp2p.go	Updates libp2pHost to accept context and conditionally apply pnet configuration
lib/ping.go	Passes context to libp2pHost call
lib/only_connect.go	Passes context to libp2pHost call
lib/identify.go	Passes context to libp2pHost call
lib/dht.go	Passes context to libp2pHost call
lib/bitswap.go	Updates CheckBitswapCID and GetBitswapCID to pass context to libp2pHost

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[codecov]

Codecov Report

❌ Patch coverage is 59.52381% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 27.16%. Comparing base (6f29ae7) to head (0375a4d).

Files with missing lines	Patch %	Lines
main.go	0.00%	10 Missing ⚠️
lib/pnet.go	80.00%	2 Missing and 2 partials ⚠️
lib/bitswap.go	33.33%	2 Missing ⚠️
lib/only_connect.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #60      +/-   ##
==========================================
+ Coverage   24.47%   27.16%   +2.69%     
==========================================
  Files           7        8       +1     
  Lines         568      578      +10     
==========================================
+ Hits          139      157      +18     
+ Misses        390      380      -10     
- Partials       39       41       +2     

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[aschmahmann]

Note: I went with the context plumbing approach mostly for ease. I'm also happy to swap this to something else (e.g. passing around libp2p options or switching to passing a host explicitly and then exposing a default constructor).