fix: CircuiTikZ loads indefinitely on desktop

[kuyacarlo]

Problem

On Linux desktop app, rendering circuits with CircuiTikZ loads indefinitely, or crashes entirely.

Technical details (Antigravity)

node-tikzjax uses a WebAssembly port of TeX with a hardcoded memory limit (pool_size = 920,271 characters). ZenNotes was pre-loading the heavy pgfplots package by default for all TikZ blocks, leaving almost no room in the string pool for loading additional large packages like circuitikz.

Changes

1. Dynamic Loading for pgfplots: Modified apps/desktop/src/main/tikz.ts to inspect the TikZ code block. pgfplots is now only loaded if the code block explicitly contains "pgfplots", "axis", or "plot".
2. Auto-detection for circuitikz: The runner now scans the code block for "circuitikz" or "ctikzset" and automatically injects the circuitikz package into texPackages. This enables circuit schematics to render out-of-the-box without requiring users to write \usepackage{circuitikz} in their note preambles.
3. No-op/Minimal Impact: Standard plots continue to load pgfplots automatically, while other diagrams (circuit diagrams, block diagrams, logic trees) gain a significant memory pool margin, resolving the compilation crashes.

Not addressed

• Circuits flash as I type it in, inside of split view mode.

Screencast.From.2026-07-08.22-26-01.mp4

CircuiTikZ Error

TikZ error: TeX engine render failed. Set `options.showConsole` to `true` to see logs.

! Emergency stop.
l.2 \ctikzset
{bipoles/length=.9cm}

CircuiTikZ Code

\ctikzset{bipoles/length=.9cm}
\begin{circuitikz}[american]
    \draw (-3,0.5) -- (3,0.5);
    \draw (0,0.5) -- (0,1) node[above]{$V_{CC}$};
    
    \draw (-3,0.5) to[R=$R_{C1}$] (-3,-1.5)
    -- (-3,-2) node[npn, anchor=C](Q1){$Q_1$};
    
    \draw (3,0.5) to[R=$R_{C2}$] (3,-1.5)
    -- (3,-2) node[npn, anchor=C, xscale=-1](Q2){%
        \scalebox{-1}[1]{$Q_2$}% Prevents label text from being mirrored
    };
    
    \draw (Q1.B) -- (-4.5, 0 |- Q1.B) 
    to[vsourcesin, l_=$v_{in1}$] (-4.5, -4.5) node[ground]{};
    
    \draw (Q2.B) -- (4.5, 0 |- Q2.B) 
    to[vsourcesin, l=$v_{in2}$] (4.5, -4.5) node[ground]{};
    
    \draw (Q1.E) |- (0,-3.5) node[circ]{} -| (Q2.E);
    
    \draw (0,-3.5) to[isource, l=$I_{EE}$] (0,-5)
    node[below]{$V_{EE}$};
\end{circuitikz}

\ctikzset{bipoles/length=.9cm}
\begin{circuitikz}[american]
  % Horizontal VCC rail (at Y = 0.5)
  \draw (-3,0.5) -- (3,0.5);
  \draw (0,0.5) -- (0,1) node[above]{$V_{CC}$};
  
  % Left branch: collector resistor RC1 down to transistor Q1
  \draw (-3,0.5) to[R=$R_{C1}$] (-3,-1.5)
  -- (-3,-2) node[npn, anchor=C](Q1){$Q_1$};
  
  % Right branch: collector resistor RC2 down to transistor Q2 (flipped horizontally)
  \draw (3,0.5) to[R=$R_{C2}$] (3,-1.5)
  -- (3,-2) node[npn, anchor=C, xscale=-1](Q2){%
      \scalebox{-1}[1]{$Q_2$} % Prevents label text from being mirrored
  };
  
  % Base inputs (clean horizontal protruding wires)
  \draw (Q1.B) -- (-4, 0 |- Q1.B) node[left]{$V_{in1}$};
  \draw (Q2.B) -- (4, 0 |- Q2.B) node[right]{$V_{in2}$};
  
  % Emitters merge orthogonally at a common node with a junction dot
  \draw (Q1.E) |- (0,-3.5) node[circ]{} -| (Q2.E);
  
  % Common emitter resistor from junction down to VEE
  \draw (0,-3.5) to[R=$R_E$] (0,-5)
  node[below]{$V_{EE}$};
\end{circuitikz}

Note: Code edited by Google Antigravity

[adibhanna]

Thanks @kuyacarlo, this is a solid fix and the mechanism is exactly right: node-tikzjax's WASM TeX engine has a fixed string-pool limit, and always pre-loading the heavy pgfplots left no room for circuitikz. Loading pgfplots only when a block references pgfplots/axis/plot, and auto-injecting circuitikz on detection, is the clean solution.

I've merged your commit into the release/v2.12.0 branch (fast-forward, so your authorship is preserved) rather than main, which is why GitHub didn't auto-close this. Closing it manually; it'll ship in v2.12.0.

Verified before merging:

• Desktop typecheck passes.
• In-app over CDP: your exact CircuiTikZ repro now renders to a valid SVG, a pgfplots axis/addplot block still renders (no regression), and basic TikZ is unaffected.

The "circuits flash while typing in split view" note is a separate, pre-existing preview-refresh quirk, not something this PR needs to address. Thanks again!

[adibhanna]

Merged into release/v2.12.0 (see comment above). Shipping in v2.11.0's successor.