chore: add missing instructions field to Pack.Info test fixtures

Root typecheck (`tsgo`) was stricter than bun test's runtime check and
flagged the two fixture objects in `pack-cli.test.ts` for missing
`instructions` — added as `undefined` so the fixtures match the Pack.Info
schema shape exactly.

No runtime behavior change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: anandgupta42

packages/opencode/test/pack/pack-cli.test.ts

@@ -134,6 +134,7 @@ describe("cleanupPackActivation — plugin refcount by canonical name", () => {
       skill_groups: {},
       mcp: {},
       plugins: ["@scope/plugin@1.2.3"],
+      instructions: undefined,
       detect: [],
       content: "",
     }
@@ -195,6 +196,7 @@ describe("cleanupPackActivation — sidecar missing (legacy fallback)", () => {
         "legacy-mcp": { type: "stdio", command: ["foo"] },
       },
       plugins: [],
+      instructions: undefined,
       detect: [],
       content: "",
     }