fix: use character limit instead of sentence split for skill description (#358)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/shared/truncate-description.test.ts

@@ -0,0 +1,104 @@
+import { describe, it, expect } from "bun:test"
+import { truncateDescription } from "./truncate-description"
+
+describe("truncateDescription", () => {
+  it("returns description unchanged when under max length", () => {
+    // given
+    const description = "This is a short description"
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result).toBe(description)
+  })
+
+  it("truncates to 120 characters by default and appends ellipsis", () => {
+    // given
+    const description = "This is a very long description that exceeds the default maximum length of 120 characters and should be truncated with an ellipsis at the end"
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result.length).toBe(123) // 120 + "..."
+    expect(result).toEndWith("...")
+    expect(result).toBe(description.slice(0, 120) + "...")
+  })
+
+  it("respects custom max length parameter", () => {
+    // given
+    const description = "This is a description that is longer than fifty characters"
+    const maxLength = 50
+
+    // when
+    const result = truncateDescription(description, maxLength)
+
+    // then
+    expect(result.length).toBe(53) // 50 + "..."
+    expect(result).toEndWith("...")
+    expect(result).toBe(description.slice(0, 50) + "...")
+  })
+
+  it("handles empty string", () => {
+    // given
+    const description = ""
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result).toBe("")
+  })
+
+  it("handles exactly max length without truncation", () => {
+    // given
+    const description = "a".repeat(120)
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result).toBe(description)
+    expect(result).not.toEndWith("...")
+  })
+
+  it("handles description with periods correctly", () => {
+    // given
+    const description = "First sentence. Second sentence. Third sentence that is very long and continues beyond the normal truncation point with even more text to ensure it exceeds 120 characters."
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result.length).toBe(123) // 120 + "..."
+    expect(result).toContain("First sentence. Second sentence.")
+    expect(result).toEndWith("...")
+  })
+
+  it("handles description with URLs correctly", () => {
+    // given
+    const description = "Check out https://example.com/very/long/path/that/contains/many/segments for more information about this feature and its capabilities"
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result.length).toBe(123) // 120 + "..."
+    expect(result).toStartWith("Check out https://example.com")
+    expect(result).toEndWith("...")
+  })
+
+  it("handles description with version numbers correctly", () => {
+    // given
+    const description = "Version 1.2.3 of the library includes many improvements and bug fixes that make it more stable and performant with additional enhancements"
+
+    // when
+    const result = truncateDescription(description)
+
+    // then
+    expect(result.length).toBe(123) // 120 + "..."
+    expect(result).toStartWith("Version 1.2.3")
+    expect(result).toEndWith("...")
+  })
+})