Fix Dirichlet variation generation to honor base material min/max bounds

[Copilot]

Dirichlet sampling could fail to produce valid variations for some materials because generated samples were effectively shaped by broad overview-sheet statistics, then normalized into values that violated the narrower per-grade element bounds. This change keeps variation generation constrained to the base material’s element ranges while still producing compositional vectors that sum to 100%.

• Bounded Dirichlet projection in sampler

  • Reworked DirichletSampler#createElementVariation to map each sample into the base composition bounds (Element.min/max) instead of relying on unconstrained normalization.
  • Added bounded solver logic to distribute mass within [min, max] and satisfy total composition = 100%.
  • Added guardrails for infeasible bounds and invalid sample shapes.

• Preserve domain constraints through generation

  • Removed the previous post-scaling approach that could push values outside element limits after normalization.
  • Ensures generated elements remain within original per-material constraints, which addresses the failure mode seen with narrow datasheet ranges.

• Regression coverage for narrow-range materials

  • Added a focused unit test in CompositionalVariationsTest to cover the case where:
    • base material ranges are tight,
    • overview statistics are broad,
    • Dirichlet output must still stay within base bounds.

// New bounded conversion path (conceptual)
double[] boundedPercentages = generateBoundedPercentages(sample, mins, maxs);
Element variationElement = new Element(
    baseElement.getName(),
    baseElement.getSymbol(),
    boundedPercentages[i],
    baseElement.getMin(),
    baseElement.getMax(),
    baseElement.getAverageComposition()
);

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• accounts.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --use-angle=swiftshader-webgl --crashpad-handler-pid=5897 --enable-crash-reporter=, --noerrdialogs --user-agent=Chrome/120.0.0.0 --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.lk2YaY --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,16022446666412780126,3040340503438469386,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --pseudonymization-salt-handle=7,i,14025070495839717569,282331497969182528,4 --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
  • Triggering command: /opt/google/chrome/chrome /usr/bin/google-chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-blink-features=AutomationControlled --disable-client-side-phishing-detection --disable-default-apps --disable-features=IgnoreDuplicateNavs,Prewarm --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-logging --headless --log-level=0 --no-first-run --no-service-autorun --password-store=basic --remote-debugging-port=0 (dns block)
• android.clients.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --use-angle=swiftshader-webgl --crashpad-handler-pid=5897 --enable-crash-reporter=, --noerrdialogs --user-agent=Chrome/120.0.0.0 --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.lk2YaY --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,16022446666412780126,3040340503438469386,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --pseudonymization-salt-handle=7,i,14025070495839717569,282331497969182528,4 --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
  • Triggering command: /opt/google/chrome/chrome /usr/bin/google-chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-blink-features=AutomationControlled --disable-client-side-phishing-detection --disable-default-apps --disable-features=IgnoreDuplicateNavs,Prewarm --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-logging --headless --log-level=0 --no-first-run --no-service-autorun --password-store=basic --remote-debugging-port=0 (dns block)
• clients2.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --use-angle=swiftshader-webgl --crashpad-handler-pid=5897 --enable-crash-reporter=, --noerrdialogs --user-agent=Chrome/120.0.0.0 --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.lk2YaY --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,16022446666412780126,3040340503438469386,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --pseudonymization-salt-handle=7,i,14025070495839717569,282331497969182528,4 --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
  • Triggering command: /opt/google/chrome/chrome /usr/bin/google-chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-blink-features=AutomationControlled --disable-client-side-phishing-detection --disable-default-apps --disable-features=IgnoreDuplicateNavs,Prewarm --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-logging --headless --log-level=0 --no-first-run --no-service-autorun --password-store=basic --remote-debugging-port=0 (dns block)
• dl.google.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)
• optimizationguide-pa.googleapis.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --use-angle=swiftshader-webgl --crashpad-handler-pid=5897 --enable-crash-reporter=, --noerrdialogs --user-agent=Chrome/120.0.0.0 --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.lk2YaY --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,16022446666412780126,3040340503438469386,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --pseudonymization-salt-handle=7,i,14025070495839717569,282331497969182528,4 --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
  • Triggering command: /opt/google/chrome/chrome /usr/bin/google-chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-blink-features=AutomationControlled --disable-client-side-phishing-detection --disable-default-apps --disable-features=IgnoreDuplicateNavs,Prewarm --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-logging --headless --log-level=0 --no-first-run --no-service-autorun --password-store=basic --remote-debugging-port=0 (dns block)
• www.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --use-angle=swiftshader-webgl --crashpad-handler-pid=5897 --enable-crash-reporter=, --noerrdialogs --user-agent=Chrome/120.0.0.0 --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.lk2YaY --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,16022446666412780126,3040340503438469386,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --pseudonymization-salt-handle=7,i,14025070495839717569,282331497969182528,4 --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
  • Triggering command: /opt/google/chrome/chrome /usr/bin/google-chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-blink-features=AutomationControlled --disable-client-side-phishing-detection --disable-default-apps --disable-features=IgnoreDuplicateNavs,Prewarm --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-logging --headless --log-level=0 --no-first-run --no-service-autorun --password-store=basic --remote-debugging-port=0 (dns block)

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