Palette & Bolt Updates (consolidated #4389 #4387 #4347 #4346 #4345 #4337)

.jules/bolt.md

@@ -89,3 +89,6 @@
 ## 2025-05-18 - Avoid array methods for small static arrays in frequently called initializers
 **Learning:** Using `.reduce()` or `.map()` on static arrays like tabs definitions inside frequently called functions (e.g. state initializers or local storage hydration) incurs unnecessary closure and function call overhead.
 **Action:** Replace `.reduce()` and `.map()` with single-pass `for` loops in simple data transformation functions (like `defaultTabVisibility`) to eliminate closure allocations.
+## 2024-07-28 - Avoid array methods for header setup during CSV parsing
+**Learning:** Using array mapping (like `.map()`) when parsing CSV header columns creates intermediate arrays, adding minor but unnecessary garbage collection pressure during the initialization phase of data visualizations.
+**Action:** Replace `.map()` calls with a single-pass `for` loop combined with pre-allocated arrays to parse dataset headers directly, minimizing closure and array allocation overhead.

.jules/palette.md

@@ -49,3 +49,6 @@
 ## 2024-05-31 - Tab Roles vs aria-pressed
 **Learning:** When implementing custom tab components in React, use `role="tab"` paired strictly with `aria-selected` (not `aria-pressed`, which is intended for toggle buttons) and ensure `aria-controls` points to a valid `role="tabpanel"` container whose `aria-labelledby` points back to the tab.
 **Action:** When adding accessible properties to custom tabs, replace `aria-pressed` with `aria-selected`, ensure a `role="tablist"` wrapper is present, and correctly cross-reference `aria-controls` with the tab panel IDs.
+## 2026-08-12 - ARIA Labels for Dynamic Matrix Grids
+**Learning:** When creating dynamic input grids (e.g., mathematical matrices or vectors) where explicit `<label>` elements per cell are impractical, screen readers are left without contextual associations for each input field.
+**Action:** Always assign descriptive, context-aware `aria-label` attributes to the inputs (e.g., `aria-label={\`Row \${i + 1}, Column \${j + 1}\`}`) to ensure screen reader accessibility without breaking the visual density of the grid.

AGENT_HANDOFF.md

@@ -1,7 +1,43 @@
 # AGENT_HANDOFF — Tools (monorepo root)
 
 > **Update this file with every PR and every push to main.**
-> Last updated: 2026-08-04
+> Last updated: 2026-08-12
+
+## 2026-08-12 — PR #4387 Data-Explorer SVG Path Construction
+
+Open PR #4387 on `bolt/optimize-svg-path-building-12382126696986403940`
+targets `main` and supersedes the narrower competing PR #4386. Line,
+scatter-trendline, and spectrum paths now build output without retaining a
+separate command array. The continuation removes prohibited code-restating
+comments, adds exact gap/empty/separator contracts across all three plots, and
+absorbs #4386's unique specification intent while explicitly avoiding an
+engine-specific garbage-collection claim.
+
+Declared Node 24 local evidence includes byte-identical old/new output and a
+30-sample post-warmup benchmark at 1,000/10,000/100,000 points. Concatenation
+medians were 0.210/1.954/17.751 ms versus array/join
+0.285/2.181/21.896 ms; at 100,000 points its median observed heap delta was
+35.093 MiB versus 36.770 MiB. Treat these as local directional evidence, not a
+cross-engine or GC-pause guarantee. All 384 frontend tests pass on Node 24,
+changed-file zero-warning ESLint and TypeScript pass, and the 1,589-module
+production build succeeds. Human review is approved; fresh final-head
+protected checks and ordinary non-admin merge behavior remain mandatory.
+
+## 2026-08-12 — PR #4389 Rotation-Converter Accessible Input Names
+
+Open PR #4389 on `palette-aria-labels-matrices-3953280844180552522`
+targets `main` with accessible names for every dense rotation and
+reference-frame numeric input. The continuation corrects the Palette note's
+date, replaces screen-reader-hostile Greek and Lie-algebra abbreviations with
+plain-language twist and rotation-vector names, and explicitly associates the
+operation, input-type, and Euler-convention labels with their controls. It also
+adds focused React contracts covering every conditional input family.
+
+Local exact-branch evidence: five focused component tests pass, including the
+initial red accessibility-name case; TypeScript, zero-warning ESLint, and the
+29-module production build pass. Human review is approved, but the final
+handoff head still requires fresh protected checks and ordinary non-admin merge
+behavior. No Rate of Closure behavior or public numerical contract changes.
 
 ## Where This Repo Is Headed
 

SPEC.md

@@ -2702,3 +2702,11 @@ The command injection check logic in `cli_tools.py` has been fortified. The inpu
 
 - Removed chained array maps and reduces in the parseVariableAssignments function within `src/web_applications/calculator/static/app.js`.
 - Improved execution speed by using standard single pass for loop and string `indexOf` / `substring` techniques.
+
+## 2026-08-12: Bounded SVG path construction
+
+- Line, scatter-trendline, and spectrum plots construct SVG path text in one
+  pass without retaining a separate command array.
+- Path-output contracts preserve segment breaks at invalid samples, command
+  order, and separator formatting; they do not claim engine-specific garbage
+  collection behavior.

launch.py

@@ -146,7 +146,9 @@ def launch_tool(tool_identifier: str) -> int:
     gui_configs = registration.gui_configs
     config = gui_configs.get(GUIType.PYQT6)
     if config is None:
-        print(f"Tool '{registration.display_name}' has no PyQt6 configuration.")  # noqa: T201
+        print(
+            f"Tool '{registration.display_name}' has no PyQt6 configuration."
+        )  # noqa: T201
         return 1
 
     display_name = registration.display_name