v2 : conception ultracode + moteur de formules porté en TS

- Blueprint définitif (docs/dev/BLUEPRINT-V2.md + JSON) : panel 4 visions
  + 3 juges, corpus doctrinal (Mon nom est personne, Une économie du don,
  SejeteralO), 4 critiques d'intégration, 3 vérificateurs, réparations
- Corpus d'intention + lectures brutes archivés
- Moteur porté Python→TS pur : threshold (inertie WoT, Smith, ComTech),
  nuancé 6 niveaux, DSL modeParams — 45 tests vitest, parité croisée
  vérifiée (Forgeron W=7224 T=120 ⇒ 94)
- Contrat de domaine v2 (types/domain.ts) + lexique UI (lexicon.ts)
- vitest + idb-keyval en dépendances

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/app/engine/modeParams.ts

@@ -0,0 +1,163 @@
+/**
+ * Mode-params DSL: parse and format compact parameter strings.
+ *
+ * Exact TypeScript port of backend/app/engine/mode_params.py
+ * (Python is the reference implementation for parsing; the Python
+ * module has no formatter, so formatModeParams() is defined as the
+ * canonical inverse of parseModeParams()).
+ *
+ * A mode-params string encodes voting formula parameters in a compact format.
+ * Example: "D30M50B.1G.2T.1"
+ *
+ * Supported codes:
+ *   D = duration_days (int)
+ *   M = majority_pct (int, 0-100)
+ *   B = base_exponent (float)
+ *   G = gradient_exponent (float)
+ *   C = constant_base (float)
+ *   S = smith_exponent (float)
+ *   T = techcomm_exponent (float)
+ *   N = ratio_multiplier (float)
+ *   R = is_ratio_mode (bool, 0 or 1)
+ *
+ * Values may start with a dot for decimals < 1, e.g. "B.1" means base_exponent=0.1.
+ */
+
+export interface ModeParams {
+  duration_days: number
+  majority_pct: number
+  base_exponent: number
+  gradient_exponent: number
+  constant_base: number
+  smith_exponent: number | null
+  techcomm_exponent: number | null
+  ratio_multiplier: number | null
+  is_ratio_mode: boolean
+}
+
+type CodeType = 'int' | 'float' | 'bool'
+
+// Ordered list of recognised codes and their target keys + types
+const CODES: Record<string, { key: keyof ModeParams; type: CodeType }> = {
+  D: { key: 'duration_days', type: 'int' },
+  M: { key: 'majority_pct', type: 'int' },
+  B: { key: 'base_exponent', type: 'float' },
+  G: { key: 'gradient_exponent', type: 'float' },
+  C: { key: 'constant_base', type: 'float' },
+  S: { key: 'smith_exponent', type: 'float' },
+  T: { key: 'techcomm_exponent', type: 'float' },
+  N: { key: 'ratio_multiplier', type: 'float' },
+  R: { key: 'is_ratio_mode', type: 'bool' },
+}
+
+// Regex: a single uppercase letter followed by a numeric value (int or float,
+// possibly starting with '.' for values like .1 meaning 0.1)
+const PARAM_RE = /([A-Z])(\d*\.?\d+)/g
+
+function getDefaults(): ModeParams {
+  return {
+    duration_days: 30,
+    majority_pct: 50,
+    base_exponent: 0.1,
+    gradient_exponent: 0.2,
+    constant_base: 0.0,
+    smith_exponent: null,
+    techcomm_exponent: null,
+    ratio_multiplier: null,
+    is_ratio_mode: false,
+  }
+}
+
+/**
+ * Parse a mode-params string into a parameter object.
+ *
+ * Defaults are applied for any code not present in the string.
+ *
+ * @param paramsStr - Compact parameter string, e.g. "D30M50B.1G.2T.1"
+ * @returns Parsed parameters with defaults for codes not found
+ * @throws Error if an unrecognised code letter is found
+ */
+export function parseModeParams(paramsStr: string): ModeParams {
+  const result = getDefaults()
+
+  if (!paramsStr || !paramsStr.trim()) {
+    return result
+  }
+
+  for (const match of paramsStr.matchAll(PARAM_RE)) {
+    const code = match[1]!
+    const rawValue = match[2]!
+
+    const entry = CODES[code]
+    if (!entry) {
+      throw new Error(`Code de parametre inconnu : '${code}'`)
+    }
+
+    const { key, type } = entry
+
+    if (type === 'int') {
+      // Python: int(float(raw)) truncates toward zero
+      ;(result as Record<keyof ModeParams, unknown>)[key] = Math.trunc(parseFloat(rawValue))
+    } else if (type === 'float') {
+      ;(result as Record<keyof ModeParams, unknown>)[key] = parseFloat(rawValue)
+    } else {
+      ;(result as Record<keyof ModeParams, unknown>)[key] = parseFloat(rawValue) !== 0.0
+    }
+  }
+
+  return result
+}
+
+/**
+ * Format a numeric value in DSL form: 0.1 -> ".1", 1 -> "1", 2.5 -> "2.5".
+ */
+function formatValue(value: number): string {
+  const s = String(value)
+  return value > 0 && value < 1 ? s.replace(/^0\./, '.') : s
+}
+
+/**
+ * Format a parameter object back into a canonical mode-params string.
+ *
+ * Canonical form matches the strings used across the project
+ * (e.g. "D30M50B.1G.2S.1"): D, M, B, G always present in that order,
+ * then C when non-zero, then S/T/N when set, then R1 when ratio mode.
+ * Round-trip: parseModeParams(formatModeParams(p)) is identical to p.
+ *
+ * @param params - Parameters to encode (missing keys take defaults)
+ * @returns Compact string, e.g. "D30M50B.1G.2"
+ */
+export function formatModeParams(params: Partial<ModeParams> = {}): string {
+  const p = getDefaults()
+  for (const key of Object.keys(p) as Array<keyof ModeParams>) {
+    const value = params[key]
+    if (value !== undefined) {
+      ;(p[key] as ModeParams[typeof key]) = value
+    }
+  }
+
+  const parts: string[] = [
+    `D${formatValue(p.duration_days)}`,
+    `M${formatValue(p.majority_pct)}`,
+    `B${formatValue(p.base_exponent)}`,
+    `G${formatValue(p.gradient_exponent)}`,
+  ]
+
+  if (p.constant_base !== 0) {
+    parts.push(`C${formatValue(p.constant_base)}`)
+  }
+  if (p.smith_exponent !== null) {
+    parts.push(`S${formatValue(p.smith_exponent)}`)
+  }
+  if (p.techcomm_exponent !== null) {
+    parts.push(`T${formatValue(p.techcomm_exponent)}`)
+  }
+  if (p.ratio_multiplier !== null) {
+    parts.push(`N${formatValue(p.ratio_multiplier)}`)
+  }
+  if (p.is_ratio_mode) {
+    parts.push('R1')
+  }
+
+  return parts.join('')
+}