refactor: apply minimal tfcode branding

- Rename packages/opencode → packages/tfcode (directory only)
- Rename bin/opencode → bin/tfcode (CLI binary)
- Rename .opencode → .tfcode (config directory)
- Update package.json name and bin field
- Update config directory path references (.tfcode)
- Keep internal code references as 'opencode' for easy upstream sync
- Keep @opencode-ai/* workspace package names

This minimal branding approach allows clean merges from upstream
opencode repository while providing tfcode branding for users.

packages/tfcode/test/server/session-list.test.ts

@@ -0,0 +1,90 @@
+import { describe, expect, test } from "bun:test"
+import path from "path"
+import { Instance } from "../../src/project/instance"
+import { Session } from "../../src/session"
+import { Log } from "../../src/util/log"
+
+const projectRoot = path.join(__dirname, "../..")
+Log.init({ print: false })
+
+describe("Session.list", () => {
+  test("filters by directory", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        const first = await Session.create({})
+
+        const otherDir = path.join(projectRoot, "..", "__session_list_other")
+        const second = await Instance.provide({
+          directory: otherDir,
+          fn: async () => Session.create({}),
+        })
+
+        const sessions = [...Session.list({ directory: projectRoot })]
+        const ids = sessions.map((s) => s.id)
+
+        expect(ids).toContain(first.id)
+        expect(ids).not.toContain(second.id)
+      },
+    })
+  })
+
+  test("filters root sessions", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        const root = await Session.create({ title: "root-session" })
+        const child = await Session.create({ title: "child-session", parentID: root.id })
+
+        const sessions = [...Session.list({ roots: true })]
+        const ids = sessions.map((s) => s.id)
+
+        expect(ids).toContain(root.id)
+        expect(ids).not.toContain(child.id)
+      },
+    })
+  })
+
+  test("filters by start time", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        const session = await Session.create({ title: "new-session" })
+        const futureStart = Date.now() + 86400000
+
+        const sessions = [...Session.list({ start: futureStart })]
+        expect(sessions.length).toBe(0)
+      },
+    })
+  })
+
+  test("filters by search term", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        await Session.create({ title: "unique-search-term-abc" })
+        await Session.create({ title: "other-session-xyz" })
+
+        const sessions = [...Session.list({ search: "unique-search" })]
+        const titles = sessions.map((s) => s.title)
+
+        expect(titles).toContain("unique-search-term-abc")
+        expect(titles).not.toContain("other-session-xyz")
+      },
+    })
+  })
+
+  test("respects limit parameter", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        await Session.create({ title: "session-1" })
+        await Session.create({ title: "session-2" })
+        await Session.create({ title: "session-3" })
+
+        const sessions = [...Session.list({ limit: 2 })]
+        expect(sessions.length).toBe(2)
+      },
+    })
+  })
+})