docs(dev): add Taskfile and developer documentation

- Add Taskfile.yml with common development tasks
- Add go-task to devbox dependencies
- Create comprehensive README-developer.md covering:
  - Devbox setup and usage
  - Hugo and Docsy basics
  - Task commands reference
  - Development workflow
  - Content creation guide
  - Testing procedures
  - Troubleshooting tips

Taskfile.yml

@@ -0,0 +1,88 @@
+version: '3'
+
+vars:
+  HUGO_CMD: hugo
+  NPM_CMD: npm
+
+tasks:
+  default:
+    desc: Show available tasks
+    cmds:
+      - task --list
+
+  # Build tasks
+  build:
+    desc: Build Hugo site
+    cmds:
+      - "{{.HUGO_CMD}} --gc --minify"
+
+  build:dev:
+    desc: Build Hugo site for development
+    cmds:
+      - "{{.HUGO_CMD}}"
+
+  serve:
+    desc: Start Hugo dev server
+    cmds:
+      - "{{.HUGO_CMD}} server"
+
+  clean:
+    desc: Clean build artifacts
+    cmds:
+      - rm -rf public resources/_gen .hugo_build.lock
+
+  # Test tasks
+  test:
+    desc: Run all tests
+    deps:
+      - test:build
+      - test:markdown
+      - test:html
+      - test:links
+
+  test:quick:
+    desc: Run quick tests (without link check)
+    deps:
+      - test:build
+      - test:markdown
+
+  test:build:
+    desc: Test Hugo build
+    cmds:
+      - "{{.HUGO_CMD}} --gc --minify --logLevel info"
+
+  test:markdown:
+    desc: Lint markdown files
+    cmds:
+      - "{{.NPM_CMD}} run test:markdown"
+
+  test:html:
+    desc: Validate HTML
+    cmds:
+      - "{{.NPM_CMD}} run test:html"
+
+  test:links:
+    desc: Check links
+    cmds:
+      - htmltest
+
+  # Development tasks
+  deps:install:
+    desc: Install all dependencies
+    cmds:
+      - "{{.NPM_CMD}} install"
+      - "{{.HUGO_CMD}} mod get -u"
+      - "{{.HUGO_CMD}} mod tidy"
+
+  deps:update:
+    desc: Update dependencies
+    cmds:
+      - devbox update
+      - "{{.NPM_CMD}} update"
+      - "{{.HUGO_CMD}} mod get -u"
+
+  # CI/CD
+  ci:
+    desc: Run CI pipeline locally
+    deps:
+      - test