feat(parser): emit verb-target-prep on 'with'/'on'/'in'/'to' separators

Enables `light lamp with matches`, `use shears on vines`, and similar
multi-noun forms. Both the target and indirect noun must resolve;
otherwise the command falls back to unknown-noun.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/engine/parser.ts

@@ -62,6 +62,24 @@ const TWO_WORD_VERBS = ['pick up']
 /** Leading stop-words stripped from the noun phrase before matching. */
 const STOP_WORDS = new Set(['at', 'the', 'a', 'an'])
 
+const PREPOSITIONS = new Set(['with', 'on', 'in', 'to'])
+
+function resolveNoun(rawTokens: string[], ctx: ParserContext): { id: string; alias: string } | null {
+  const phrase = rawTokens.join(' ')
+  if (phrase === 'it' && ctx.lastNoun) {
+    return { id: ctx.lastNoun.canonical, alias: 'it' }
+  }
+  for (const noun of ctx.visibleNouns) {
+    for (const alias of noun.aliases) {
+      if (alias === phrase) return { id: noun.id, alias }
+    }
+  }
+  for (const itemId of ctx.inventoryItemIds) {
+    if (itemId === phrase) return { id: itemId, alias: phrase }
+  }
+  return null
+}
+
 function tokenize(input: string): string[] {
   return input.trim().toLowerCase().split(/\s+/).filter(Boolean)
 }
@@ -141,6 +159,33 @@ export function parse(rawInput: string, ctx: ParserContext): ParsedCommand {
     return { kind: 'unknown', raw: trimmed, reason: 'malformed' }
   }
 
+  // Detect a preposition splitting target | indirect.
+  const prepIdx = rest.findIndex((tok) => PREPOSITIONS.has(tok))
+  if (prepIdx > 0 && prepIdx < rest.length - 1) {
+    const targetTokens = rest.slice(0, prepIdx)
+    const prep = rest[prepIdx]!
+    let indirectTokens = rest.slice(prepIdx + 1)
+    // Strip stop-words at the head of the indirect phrase too ("on the table").
+    while (indirectTokens.length > 0 && STOP_WORDS.has(indirectTokens[0]!)) {
+      indirectTokens = indirectTokens.slice(1)
+    }
+    if (indirectTokens.length > 0) {
+      const target = resolveNoun(targetTokens, ctx)
+      const indirect = resolveNoun(indirectTokens, ctx)
+      if (target && indirect) {
+        return {
+          kind: 'verb-target-prep',
+          verb,
+          target: { canonical: target.id, raw: target.alias },
+          preposition: prep,
+          indirect: { canonical: indirect.id, raw: indirect.alias },
+        }
+      }
+      // Either side failed to resolve → fall through to unknown-noun below.
+      return { kind: 'unknown', raw: trimmed, reason: 'unknown-noun' }
+    }
+  }
+
   // Pronoun resolution: "it" maps to lastNoun.
   if (rest.length === 1 && rest[0] === 'it') {
     if (!ctx.lastNoun) {