refactor(shared): move parseModelString out of delegate-task to break cross-tool coupling

Move parseModelString into src/shared so callers can depend on a neutral module instead of reaching into delegate-task internals.

Cross-tool coupling violates module boundaries, and this keeps call-omo-agent plus runtime-fallback from importing through a sibling tool.

src/hooks/runtime-fallback/retry-model-payload.ts

@@ -1,4 +1,4 @@
-import { parseModelString } from "../../tools/delegate-task/model-string-parser"
+import { parseModelString } from "../../shared/model-string-parser"
 
 export function buildRetryModelPayload(
   model: string,

src/shared/index.ts

@@ -78,3 +78,4 @@ export * from "./plugin-identity"
 export * from "./log-legacy-plugin-startup-warning"
 export * from "./task-system-enabled"
 export * from "./parse-tools-config"
+export { parseModelString } from "./model-string-parser"

src/tools/call-omo-agent/tools.ts

@@ -1,6 +1,6 @@
 import { tool, type PluginInput, type ToolDefinition } from "@opencode-ai/plugin"
 import { ALLOWED_AGENTS, CALL_OMO_AGENT_DESCRIPTION } from "./constants"
-import type { AllowedAgentType, CallOmoAgentArgs, ToolContextWithMetadata } from "./types"
+import type { CallOmoAgentArgs, ToolContextWithMetadata } from "./types"
 import type { BackgroundManager } from "../../features/background-agent"
 import type { CategoriesConfig, AgentOverrides } from "../../config/schema"
 import type { DelegatedModelConfig } from "../../shared/model-resolution-types"
@@ -11,7 +11,7 @@ import { normalizeFallbackModels } from "../../shared/model-resolver"
 import { buildFallbackChainFromModels } from "../../shared/fallback-chain-from-models"
 import { log } from "../../shared"
 import { CONFIG_BASENAME } from "../../shared/plugin-identity"
-import { parseModelString } from "../delegate-task/model-string-parser"
+import { parseModelString } from "../../shared"
 import { executeBackground } from "./background-executor"
 import { executeSync } from "./sync-executor"
 import { resolveCallableAgents } from "./agent-resolver"

src/tools/delegate-task/category-resolver.ts

@@ -5,7 +5,7 @@ import type { FallbackEntry } from "../../shared/model-requirements"
 import { mergeCategories } from "../../shared/merge-categories"
 import { SISYPHUS_JUNIOR_AGENT } from "./sisyphus-junior-agent"
 import { resolveCategoryConfig } from "./categories"
-import { parseModelString } from "./model-string-parser"
+import { parseModelString } from "../../shared/model-string-parser"
 import { CATEGORY_MODEL_REQUIREMENTS } from "../../shared/model-requirements"
 import { normalizeFallbackModels, flattenToFallbackModelStrings } from "../../shared/model-resolver"
 import { buildFallbackChainFromModels, findMostSpecificFallbackEntry } from "../../shared/fallback-chain-from-models"

src/tools/delegate-task/model-selection.ts

@@ -4,7 +4,7 @@ import { fuzzyMatchModel } from "../../shared/model-availability"
 import { transformModelForProvider } from "../../shared/provider-model-id-transform"
 import { hasConnectedProvidersCache, hasProviderModelsCache, readConnectedProvidersCache } from "../../shared/connected-providers-cache"
 import { log } from "../../shared/logger"
-import { parseModelString, parseVariantFromModelID } from "./model-string-parser"
+import { parseModelString, parseVariantFromModelID } from "../../shared/model-string-parser"
 
 function isExplicitHighModel(model: string): boolean {
   return /(?:^|\/)[^/]+-high$/.test(model)