fix(opencode): preserve skill resource paths

packages/opencode/src/command/index.ts

@@ -1,4 +1,5 @@
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
+import path from "path"
 import { InstanceState } from "@/effect/instance-state"
 import { EffectBridge } from "@/effect/bridge"
 import type { InstanceContext } from "@/project/instance-context"
@@ -132,12 +133,19 @@ export const layer = Layer.effect(
 
       for (const item of yield* skill.all()) {
         if (commands[item.name]) continue
+        const dir = item.location === "<built-in>" ? undefined : path.dirname(item.location)
         commands[item.name] = {
           name: item.name,
           description: item.description,
           source: "skill",
           get template() {
-            return item.content
+            if (!dir) return item.content
+            return [
+              item.content,
+              "",
+              `Base directory for this skill: ${dir}`,
+              "Relative paths in this skill (e.g., scripts/, references/) are relative to this base directory.",
+            ].join("\n")
           },
           hints: [],
         }

packages/opencode/src/skill/index.ts

@@ -1,6 +1,5 @@
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import path from "path"
-import { pathToFileURL } from "url"
 import { Effect, Layer, Context, Schema } from "effect"
 import { NamedError } from "@opencode-ai/core/util/error"
 import type { Agent } from "@/agent/agent"
@@ -17,6 +16,7 @@ import { RuntimeFlags } from "@/effect/runtime-flags"
 import { Glob } from "@opencode-ai/core/util/glob"
 import { Discovery } from "./discovery"
 import { isRecord } from "@/util/record"
+import { escapeHtml } from "@/util/html"
 
 const CLAUDE_EXTERNAL_DIR = ".claude"
 const AGENTS_EXTERNAL_DIR = ".agents"
@@ -339,7 +339,7 @@ export function fmt(list: Info[], opts: { verbose: boolean }) {
           "  <skill>",
           `    <name>${skill.name}</name>`,
           `    <description>${skill.description}</description>`,
-          `    <location>${pathToFileURL(skill.location).href}</location>`,
+          `    <location>${escapeHtml(skill.location)}</location>`,
           "  </skill>",
         ]),
       "</available_skills>",

packages/opencode/test/skill/skill.test.ts

@@ -77,6 +77,33 @@ const withHome = <A, E, R>(home: string, self: Effect.Effect<A, E, R>) =>
   )
 
 describe("skill", () => {
+  it.effect("formats verbose locations as XML-safe filesystem paths", () =>
+    Effect.sync(() => {
+      const output = Skill.fmt(
+        [
+          {
+            name: "tagged-skill",
+            description: "A tagged skill.",
+            location: "/tmp/plugin.git#v1.3.0/SKILL.md",
+            content: "",
+          },
+          {
+            name: "built-in-skill",
+            description: "A built-in skill.",
+            location: "<built-in>",
+            content: "",
+          },
+        ],
+        { verbose: true },
+      )
+
+      expect(output).toContain("<location>/tmp/plugin.git#v1.3.0/SKILL.md</location>")
+      expect(output).toContain("<location>&lt;built-in&gt;</location>")
+      expect(output).not.toContain("file://")
+      expect(output).not.toContain("%23")
+    }),
+  )
+
   it.live("discovers skills from .opencode/skill/ directory", () =>
     provideTmpdirInstance(
       (dir) =>