fix: remove fabricated precision and size fallbacks from Ollama metadata

docs/ranking-contract-validation.md

@@ -6,7 +6,7 @@ registry recommendations, and the desktop source now tracked in this repository.
 
 | Case | Corrected behavior | Regression coverage |
 | --- | --- | --- |
-| Artifact precision and size | FP16/BF16/FP32 retain their precision. A fixed Q8 file cannot become Q5 to fit a budget. Complete shard sets contribute their combined size; incomplete sets are excluded. Unknown precision without a known size is ineligible. | `ranking-contract.test.js`, `selector-memory-sizing.test.js`, `deterministic-model-pool-check.js` |
+| Artifact precision and size | FP16/BF16/FP32 retain their precision. A fixed Q8 file cannot become Q5 to fit a budget. Complete shard sets contribute their combined size; incomplete sets are excluded. Unknown precision without a known size is ineligible. Missing Ollama metadata no longer invents a 4 GB Q4 artifact, and full-precision resident weights cannot shrink to a stale download-size estimate. | `ranking-contract.test.js`, `selector-memory-sizing.test.js`, `deterministic-model-pool-check.js` |
 | Model capabilities | Embeddings and rerankers are excluded from generation categories; missing capability data does not imply generation. | `ranking-contract.test.js` |
 | Benchmark identity | Base, Instruct, size, revision, thinking, and context-extension variants remain distinct. Unsized family measurements cannot score a smaller checkpoint. Quantized repos require an explicit quantization alias to inherit upstream measurements. | `quality-evals.test.js`, `ranking-contract.test.js` |
 | Accelerator scoring | ROCm, Vulkan and SYCL have explicit estimate profiles. CPU-only mode suppresses accelerator scoring. | `ranking-contract.test.js`, `cpu-only-mode.test.js` |

src/data/registry-ingestors.js

@@ -779,6 +779,7 @@ module.exports = {
     normalizeOllamaRows,
     inferFormat,
     inferQuantization,
+    inferPrecision,
     inferRuntimeSupport,
     isModelArtifactFile,
     parseParamsB,

src/data/registry-recommender.js

@@ -1,5 +1,5 @@
 const ModelDatabase = require('./model-database');
-const { isSupportedHuggingFaceModel } = require('./registry-ingestors');
+const { isSupportedHuggingFaceModel, inferQuantization, inferPrecision } = require('./registry-ingestors');
 const DeterministicModelSelector = require('../models/deterministic-selector');
 const { normalizePrecision, memoryBudgetGB } = require('../models/ranking-contract');
 const { applyCpuOnlyOverride } = require('../hardware/cpu-only');
@@ -93,7 +93,8 @@ function inferFamily(identifier = '') {
 }
 
 function normalizeQuantization(row = {}) {
-    const raw = row.quantization || row.precision || '';
+    const filename = row.filename || row.artifact_name || '';
+    const raw = inferQuantization(filename) || inferPrecision(filename) || row.quantization || row.precision || '';
     return normalizePrecision(raw);
 }
 

src/models/deterministic-selector.js

@@ -1135,7 +1135,7 @@ class DeterministicModelSelector {
         return this.normalizeQuantization(
             variant.quantization ||
             variant.quant ||
-            'Q4_K_M'
+            'UNKNOWN'
         );
     }
 
@@ -1210,10 +1210,9 @@ class DeterministicModelSelector {
     }
 
     extractVariantSizeGB(variant, paramsB) {
-        const candidate = Number(variant.real_size_gb ?? variant.estimated_size_gb ?? variant.size_gb ?? NaN);
+        const candidate = Number(variant.real_size_gb ?? variant.size_gb ?? NaN);
         if (Number.isFinite(candidate) && candidate > 0) return candidate;
-        if (!Number.isFinite(paramsB) || paramsB <= 0) return 0.5;
-        return Math.max(0.5, Math.round((paramsB * 0.58 + 0.5) * 10) / 10);
+        return null; // No observed artifact size; estimate from the actual precision later.
     }
 
     inferModalities(model, variantTag = '') {
@@ -1303,27 +1302,27 @@ class DeterministicModelSelector {
 
     extractParams(details) {
         // Look for parameter info in ollama show output
-        const match = details.match(/parameters\s+(\d+\.?\d*)[BM]/i);
+        const match = details.match(/parameters\s+(\d+\.?\d*)\s*[BM]/i);
         if (match) {
             const num = parseFloat(match[1]);
             return match[0].toUpperCase().includes('B') ? num : num / 1000;
         }
-        return 7; // Default fallback
+        return null;
     }
 
     extractContextLength(details) {
-        const match = details.match(/context_length\s+(\d+)/i);
-        return match ? parseInt(match[1]) : 4096;
+        const match = details.match(/context[ _]length\s+(\d+)/i);
+        return match ? parseInt(match[1]) : null;
     }
 
     extractQuantization(details) {
-        const match = details.match(/quantization\s+(Q\d+_[A-Z0-9_]+)/i);
-        return match ? match[1] : 'Q4_K_M';
+        const match = details.match(/quantization\s+(\S+)/i);
+        return normalizePrecision(match?.[1]);
     }
 
     extractSizeGB(details) {
-        const match = details.match(/size\s+(\d+\.?\d*)\s*GB/i);
-        return match ? parseFloat(match[1]) : 4.0;
+        const match = details.match(/size\s+(\d+\.?\d*)\s*(GB|MB)/i);
+        return match ? parseFloat(match[1]) / (match[2].toUpperCase() === 'MB' ? 1024 : 1) : null;
     }
 
     extractModalities(details) {
@@ -1584,6 +1583,7 @@ class DeterministicModelSelector {
     }
 
     evaluateModel(model, hardware, category, targetCtx, budget, optimizeFor = 'balanced', runtime = 'ollama', options = {}) {
+        if (!(this.parseBillionsValue(model.totalParamsB || model.paramsB) > 0)) return null;
         const nativeContext = Number(model.ctxMax);
         const requiredContext = options.contextPolicy !== 'preferred';
         if (requiredContext && (!(nativeContext > 0) || nativeContext < targetCtx)) return null;
@@ -1674,7 +1674,9 @@ class DeterministicModelSelector {
         // A model/tag/file is an immutable artifact. Alternative files are separate rows.
         if (model?.quant) return [this.normalizeQuantization(model.quant)];
         const available = model?.availableQuantizations || Object.keys(model?.sizeByQuant || {});
-        if (!available.length && Number(model?.sizeGB) > 0) return ['UNKNOWN'];
+        if (available.length !== 1 && (model?.model_identifier || !available.length)) {
+            return Number(model?.sizeGB) > 0 ? ['UNKNOWN'] : [];
+        }
         return [...new Set(available.map(normalizePrecision))]
             .sort((a, b) => (precisionProfile(b).bytes || 0) - (precisionProfile(a).bytes || 0));
     }
@@ -1716,9 +1718,11 @@ class DeterministicModelSelector {
                 ? parameterProfile.totalParamsB
                 : parameterProfile.effectiveParamsB;
         const modeledWeightGB = bpp == null ? Infinity : weightParamsB * bpp;
-        // A real observed artifact size always wins for weight memory — never let
-        // an MoE "sparse inference" assumption discard a measured on-disk size.
-        const useObservedArtifactSize = Number.isFinite(observedWeightGB) && observedWeightGB > 0;
+        // Full-precision resident weights cannot shrink to a compressed download
+        // or an old Q4 size estimate. Quantized artifacts retain their observed size.
+        const fullPrecision = ['FP16', 'BF16', 'FP32'].includes(normalizedQuant);
+        const useObservedArtifactSize = Number.isFinite(observedWeightGB) && observedWeightGB > 0 &&
+            (!fullPrecision || observedWeightGB >= modeledWeightGB);
         const modelMemGB = useObservedArtifactSize ? observedWeightGB : modeledWeightGB;
         const effectiveCtx = Number.isFinite(Number(ctx)) && Number(ctx) > 0 ? Number(ctx) : 4096;
 

src/ollama/native-scraper.js

@@ -569,7 +569,7 @@ class OllamaNativeScraper {
                     quantization: quantization,
                     command: `ollama pull ${tag}`,
                     estimated_size_gb: this.estimateModelSizeGB(tag),
-                    real_size_gb: realSizeGB || this.estimateModelSizeGB(tag)
+                    real_size_gb: realSizeGB || null
                 };
             });
 
@@ -586,8 +586,8 @@ class OllamaNativeScraper {
     }
 
     extractQuantizationFromTag(tag) {
-        const quantMatch = tag.match(/\b(q\d+_[km]?_?[ms]?|fp16|fp32|int8|int4)\b/i);
-        return quantMatch ? quantMatch[0].toUpperCase() : 'Q4_0'; // Default assumption
+        const quantMatch = tag.match(/\b(i?q\d+(?:_[a-z0-9]+)*|bf16|f16|f32|fp16|fp32|int8|int4)\b/i);
+        return quantMatch ? quantMatch[0].toUpperCase() : 'UNKNOWN';
     }
 
     extractRealSizeFromHTML(html, tag) {

tests/ranking-contract.test.js

@@ -19,6 +19,22 @@ for (const quant of ['FP16', 'BF16', 'FP32']) {
     assert.strictEqual(selector.evaluateModel({ ...base, quant }, hardware, 'general', 4096, 8), null);
 }
 assert.strictEqual(precisionProfile('IQ4_XS').bytes, 0.58);
+assert.strictEqual(selector.extractQuantization('quantization F16'), 'FP16');
+assert.ok(selector.estimateRequiredGB({ ...base, sizeGB: 4 }, 'FP16', 4096) > 14, 'a stale Q4 size must not shrink FP16 resident weights');
+assert.strictEqual(selector.extractQuantization('quantization BF16'), 'BF16');
+assert.strictEqual(selector.extractQuantization(''), 'UNKNOWN');
+assert.strictEqual(selector.extractSizeGB(''), null);
+assert.strictEqual(selector.extractParams('parameters 7 B'), 7);
+assert.strictEqual(selector.evaluateModel({ ...base, paramsB: null, sizeGB: 4 }, hardware, 'general', 4096, 8), null);
+assert.strictEqual(selector.extractContextLength(''), null);
+assert.strictEqual(selector.extractVariantSizeGB({ estimated_size_gb: 4 }, 7), null);
+const fpVariant = selector.convertOllamaModelToDeterministicModels({ model_identifier: 'test', primary_category: 'general',
+    variants: [{ tag: 'test:7b-fp16', quantization: 'FP16', size: '7b' }] })[0];
+assert.strictEqual(fpVariant.quant, 'FP16');
+assert.ok(selector.estimateRequiredGB(fpVariant, 'FP16', 4096) > 14);
+assert.strictEqual(selector.selectBestQuantization(fpVariant, 8, 4096), null);
+assert.deepStrictEqual(selector.getQuantizationCandidates({ model_identifier: 'unknown:7b', availableQuantizations: ['Q8_0', 'Q4_K_M'] }), []);
+
 assert.strictEqual(selector.estimateRequiredGB({ ...base, quant: 'unknown' }, 'unknown', 4096), Infinity);
 const fixed = { ...base, quant: 'Q8_0', model_identifier: 'qwen:7b-q8_0',
     availableQuantizations: ['Q8_0', 'Q4_K_M'], sizeByQuant: { Q8_0: 7.6, Q4_K_M: 4.5 } };
@@ -32,6 +48,9 @@ const shard = { source_id: 'huggingface', repo_id: 'test/model-7B-GGUF',
     canonical_model_id: 'test/model-7B-GGUF', repo_tasks: ['text-generation'], format: 'gguf',
     quantization: 'Q8_0', size_gb: 4, parameter_count_b: 7, context_length: 4096,
     runtime_support: ['ollama', 'llama.cpp'] };
+const stalePrecision = artifactToSelectorModel({ ...shard, filename: 'model-7b-f16.gguf', quantization: 'Q4_K_M' });
+assert.strictEqual(stalePrecision.quant, 'FP16', 'the concrete file precision overrides stale metadata');
+assert.ok(selector.estimateRequiredGB(stalePrecision, 'FP16', 4096) > 14);
 const shards = [1, 2].map(i => ({ ...shard, filename: `model-Q8_0-0000${i}-of-00002.gguf` }));
 assert.strictEqual(groupWeightShards(shards.slice(1)).length, 0, 'incomplete shard sets are not installable');
 const grouped = groupWeightShards(shards);