feat: Add live-coding support via nREPL and SSE reload

Message

Add the infrastructure for live-coding Sigil web applications. An AI agent or editor connects to a running app's nREPL, redefines handlers or views, and triggers a browser refresh — no page reload needed.

New modules: - (sigil web dev): Dev broadcast channel, dev-reload!, dev-morph!, dev-error!, dev-sse-handler for SSE-based browser refresh - (sigil nrepl client): Reusable nREPL client for connecting to running Sigil apps over TCP - (sigil mcp dev-tools): MCP tools (dev-connect, dev-eval, dev-reload, dev-status, dev-disconnect) that proxy to nREPL

Changes: - (sigil web ui): Add sse-reload event for page re-fetch + Idiomorph morph - sigil-web-ui.js: Handle sigil:reload event with fetch + morph cycle - Vinyl Vault demo: Wire up nREPL server (port 7888) and dev SSE endpoint

Changed

 package.sgl                  |  1 +
 src/sigil/web/demo.sgl       | 17 +++++++++++++++--
 src/sigil/web/demo/views.sgl |  3 ++-
 3 files changed, 18 insertions(+), 3 deletions(-)

Diff

package.sglmodified

@@ -16,6 +16,7 @@

16

(from-workspace name: "sigil-stdlib")

17

(from-workspace name: "sigil-http")

18

(from-workspace name: "sigil-web")

+19

(from-workspace name: "sigil-nrepl")

20

(from-workspace name: "sigil-sqlite")

21

(from-workspace name: "sigil-sxml")

22

(from-workspace name: "sigil-css")))

src/sigil/web/demo.sglmodified

@@ -15,6 +15,8 @@

15

(sigil http request)

16

(sigil web)

17

(sigil web ui)

+18

(sigil web dev)

+19

(sigil nrepl)

20

(sigil sqlite)

21

(sigil web demo db)

22

(sigil web demo views))

@@ -222,7 +224,8 @@

224

(route method: POST pattern: "/records" handler: create-record-handler)

225

(route method: POST pattern: "/records/:id" handler: update-record-handler)

226

(route method: DELETE pattern: "/records/:id" handler: delete-record-handler)

−225

(route method: GET pattern: "/js/sigil-web-ui.js" handler: (sigil-web-ui-handler))))

+227

(route method: GET pattern: "/js/sigil-web-ui.js" handler: (sigil-web-ui-handler))

+228

(route method: GET pattern: "/__dev/events" handler: (dev-sse-handler))))

229

(with-db _ db)

230

(with-logging)

231

(with-content-type default: "text/html; charset=utf-8")

@@ -230,10 +233,20 @@

233

234

;;; Start the demo server.

235

(define (start-demo)

−233

(let ((db (sqlite-open "vinyl-vault.db")))

+236

(let ((db (sqlite-open "vinyl-vault.db"))

+237

(dev (make-dev-broadcast)))

238

(init-db db)

239

(display "Vinyl Vault running at http://localhost:8080\n")

+240

(display "nREPL at port 7888\n")

241

(with-async

+242

;; nREPL goroutine

+243

(let ((nrepl (nrepl-start 7888)))

+244

(when nrepl

+245

(go (let loop ()

+246

(nrepl-process-pending nrepl)

+247

(sleep 0.05)

+248

(loop)))))

+249

;; HTTP server

250

(http-serve (make-app db) port: 8080))))

251

252

))

src/sigil/web/demo/views.sglmodified

@@ -393,7 +393,8 @@

393

(li (a (@ (href "/records/new")) "Add Record")))))

394

(div (@ (id "sg-flash-container")))

395

(main (@ (class "container"))

−396

,body-content))))

+396

,body-content)

+397

(div (@ (data-sg-sse "/__dev/events") (style "display:none"))))))

398

399

;; ============================================================

400

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