add js/wasm browser build with OpenRouter PKCE, agentic loop, and demo page

[dgageot]

What this is

A GOOS=js GOARCH=wasm entry point under cmd/wasm that exposes a slice of docker-agent — config parsing plus a streaming agentic loop with tool calling — to a JavaScript host (browser or Node). It is a proof-of-concept, not a port of the full agent (see Limits below).

The static demo at cmd/wasm/web/index.html runs against OpenRouter via the PKCE OAuth flow.

See cmd/wasm/README.md for full build / run instructions and architecture notes.

What it does

• Config parsing (any version → latest via pkg/config)
• Agent enumeration (lists agents, models, instructions)
• Full agentic loop: streaming chat with tool calling, multi-agent handoffs, fallback models with retry + backoff, hooks (session_start, turn_start, pre_tool_use, post_tool_use)
• Remote MCP tools (HTTP/SSE transport — no stdio)
• Request cancellation via dockerAgent.abort()

A JS API is registered on globalThis.dockerAgent:

dockerAgent.parseConfig(yamlString)
dockerAgent.listAgents(yamlString)
dockerAgent.chat({yaml, agentName?, env?, messages}, onEvent)
dockerAgent.abort()

What it intentionally does NOT do

• Run shell commands (no os/exec under js/wasm)
• Open files or listen on sockets
• Persist sessions to sqlite
• Render a TUI
• Use pkg/runtime or pkg/teamloader directly (both are blocked by sqlite under wasm) — instead cmd/wasm/runtime_wasm.go builds agents from config using pkg/agent directly and runs a simplified streaming loop

Build & test

# Compile (~94 MB unoptimised .wasm).
GOOS=js GOARCH=wasm go build -o cmd/wasm/web/docker-agent.wasm ./cmd/wasm

# Copy the matching shim from the Go toolchain.
cp "\$(go env GOROOT)/lib/wasm/wasm_exec.js" cmd/wasm/web/wasm_exec.js

# Node smoke test (proves runtime + parseConfig + listAgents + abort work).
node cmd/wasm/smoke_test.js

The generated artifacts (cmd/wasm/web/docker-agent.wasm, cmd/wasm/web/wasm_exec.js, and a wasm debug binary) are in .gitignore — they are built locally.

Cross-platform plumbing this required

Several packages had unix-only files that incidentally matched GOOS=js. To make the wasm target compile, a small set of _js.go stubs was added alongside the existing _unix.go / _windows.go files:

• pkg/cache/lock_js.go — file-lock no-op (single-process under wasm)
• pkg/desktop/connection_js.go + sockets_js.go — Docker Desktop connection stubs
• pkg/desktop/connection_other.go — tightened build tag to !windows && !js
• pkg/model/provider/factory_js.go — provider factory without OS-specific deps
• pkg/tools/builtin/shell/cmd_js.go — process-group stubs
• pkg/tools/builtin/shell/cmd_unix.go — tightened build tag to !windows && !js (it was using `syscall.SysProcAttr.Setpgid` which doesn't exist under js/wasm)

Validation

• `go build ./...` — ok
• `GOOS=js GOARCH=wasm go build -o cmd/wasm/web/docker-agent.wasm ./cmd/wasm` — ok
• `GOOS=windows go build ./...` — ok
• `task test` — all packages pass
• `task lint` — 0 issues
• `node cmd/wasm/smoke_test.js` — OK — all smoke tests pass (parseConfig, listAgents, abort)

Assisted-By: docker-agent

[docker-agent]

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