fix(cli): scope doctor session/db discovery to HOME/XDG overrides

Pi recent-session discovery and the OpenCode db probe resolved through
bare homedir(), which ignores a runtime HOME override. A doctor run in
a sandboxed environment (like the doctor tests) escaped to the real
~/.pi/agent/sessions and surfaced the machine's historian debug dumps,
adding a nondeterministic WARN to otherwise-isolated runs.

Co-authored-by: Alfonso [Magic Context] <288211368+alfonso-magic-context@users.noreply.github.com>

Author: ualtinok

packages/cli/src/lib/diagnostics-opencode.ts

@@ -438,7 +438,10 @@ function collectHistorianDumps(
  * historian dumps fall back to the legacy tmp-dir listing on the empty path.
  */
 async function collectRecentSessions(): Promise<RecentSessionSummary[]> {
-    const opencodeDbPath = join(homedir(), ".local", "share", "opencode", "opencode.db");
+    // env-first: honor XDG/HOME overrides (and sandboxed doctor test runs)
+    // instead of Bun's homedir(), which ignores a runtime HOME override.
+    const dataHome = process.env.XDG_DATA_HOME || join(process.env.HOME || homedir(), ".local", "share");
+    const opencodeDbPath = join(dataHome, "opencode", "opencode.db");
     if (!existsSync(opencodeDbPath)) return [];
 
     if (typeof (globalThis as { Bun?: unknown }).Bun === "undefined") {

packages/cli/src/lib/diagnostics-pi.ts

@@ -284,7 +284,10 @@ function reverseSlugToDirectory(slug: string): string | null {
  * doesn't exist (Pi not installed or never used).
  */
 function collectPiRecentSessions(): PiRecentSessionSummary[] {
-    const sessionsRoot = join(homedir(), ".pi", "agent", "sessions");
+    // env-first like the rest of this file: Bun's homedir() does not follow a
+    // runtime HOME override, which would let sandboxed doctor runs escape to
+    // the real ~/.pi/agent/sessions.
+    const sessionsRoot = join(process.env.HOME || homedir(), ".pi", "agent", "sessions");
     if (!existsSync(sessionsRoot)) return [];
     try {
         const slugs = readdirSync(sessionsRoot, { withFileTypes: true })