feat: add multi-port support for parallel server instances

[cs50victor]

Add --port and --cdp-port CLI flags to server.sh to enable running multiple dev-browser instances in parallel. This allows different subagents to each control their own browser instance.

Usage:
./server.sh --port 9222 # instance 1
./server.sh --port 9224 # instance 2 (parallel)

CDP port defaults to port + 1 unless explicitly set via --cdp-port.

[mattheworiordan]

I have hit this same issue, I regularly have sub-agents doing work to speed things up, and discovered that dev-browser is in fact a single point of congestion now, nullifying the advantages of dev browser.

Your approach @cs50victor could work, but then that requires agents to manage the assignment of ports based on availability and awareness of other sub-agents to doing work.

I wonder if there's a better way, such as:

• Starting the server auto-discovers a new port, and returns that to the agent. So the agent no longer has a default port, but always just waits for the server to confirm the new port before it starts. I suspect this is cleanest.
• Introduce support in dev-browser for the named page registry which already exists const registry = new Map<string, PageEntry>() ->

  dev-browser/skills/dev-browser/src/index.ts

  Lines 101 to 102 in b549fb0

  	// Registry: name -> PageEntry
  	const registry = new Map<string, PageEntry>();

  . In theory each agent could just define a unique ID and use that.

@SawyerHood interested in your thoughts on this.

[cs50victor]

auto port discovery would make the skill a lot easier for the model to use. I second this redesign.

[mattheworiordan]

auto port discovery would make the skill a lot easier for the model to use. I second this redesign.

See #24.
Hoping that is merged!