feat: variable inspector, plot viewer, SciML snippets, CI (v0.2.0)

[singhharsh1708]

Summary

• Variable Inspector — after every Run Block, a side panel auto-opens showing all live Main bindings (name / type / size / value preview). Julia appends VAR_INSPECT_SUFFIX to each block; parseVariables() extracts the delimited output.
• Plot Viewer — if the block uses Plots.jl or CairoMakie, the figure is saved to a temp PNG and shown in a WebView side panel automatically. Re-run to refresh.
• SciML Snippets — CompletionItemProvider for Julia files with 8 prefixes: ode, sde, mtk, neural_ode, bvp, optim, pinn, diffeq → full boilerplate on Tab.
• GitHub Actions CI — compile + typecheck + package on every push/PR; auto-attach .vsix to GitHub Releases on v*.*.* tags.

New files

• src/variableInspector.ts
• src/plotViewer.ts
• src/snippets.ts
• .github/workflows/ci.yml

Test plan

• Run Block on a cell that defines variables → Variable Inspector panel opens with correct names/types
• Run Block on a cell with plot(...) → Plot Viewer panel opens with the figure
• Run Block on a cell with no plot → Plot Viewer does NOT open
• Type ode in a .jl file → snippet appears in completion list, Tab expands full boilerplate
• Type neural_ode → Lux.jl boilerplate expands correctly
• Push to main → CI workflow triggers and packages the extension
• Compile check: npx tsc -p . no errors

🤖 Generated with Claude Code