[FEATURE] Visible, user-referenceable session ID + alias for cross-session, cross-project work

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Summary

Surface a visible, stable, user-referenceable session identifier in the Claude Code desktop app — plus an optional user-defined alias — that can be used to cross-reference sessions (within and across projects) and carried through into exported documentation/output. Today sessions are navigable only by auto-generated titles, which doesn't scale once work fans out across many sessions and multiple related projects.

Problem / motivation

My work routinely splits across many sessions, and sometimes across several projects that share one tech stack (a suite of related repos). I keep needing to return to, and reference, the outcome of a specific earlier session — e.g. a deep architecture/planning session whose decisions later execution sessions depend on.

Two things make that hard today:

1. The session ID isn't visible. The sidebar shows sessions by auto-generated title only. The underlying session ID (local_<uuid>) isn't shown or copyable anywhere in the desktop UI — it's only discoverable via the on-disk path or internal tooling.
2. Titles are a poor handle. They're auto-generated and often don't convey the session's actual content, so I can't reliably identify or cross-reference a session from its title — especially months later, or when several sessions in a project sound similar.

There's also no first-class way to reference one session from another, or to embed a session reference in an external artifact (a design doc or generated report) so the artifact links back to the session that produced it.

Current behavior

• Desktop sidebar lists sessions grouped by project, labelled by auto-generated title.
• Session ID is not displayed or copyable in the app.
• No stable, user-editable reference exists; titles auto-generate and aren't dependable handles.

Proposed Solution

Proposed solution

A "session reference" capability, roughly in priority order:

1. Visible, copyable session ID — show it in the session header/details with a one-click copy button.
2. User-definable alias — let me set a short, stable, memorable reference on a session (e.g. FX-ARCH-001), shown in the sidebar alongside the title and independent of the auto-generated title. A project prefix would help.
3. Cross-session referencing — make it easy to reference/jump to another session by ID or alias, and to resolve/search by that reference, including across projects (the shared-suite case).
4. Carry-through to documentation/output — expose the ID/alias to hooks and exports so a generated doc/report can embed a back-reference to its originating session, and that reference can be used to return to the session. (E.g. session ID available to SessionStart hooks; a "copy reference" action producing a stable, doc-embeddable token/link.)

Alternative Solutions

Alternatives I currently use (and why they fall short)

• Titles — auto-generated, often non-descriptive, not stable handles.
• Full-text transcript search — works, but returns snippets and depends on remembering a distinctive phrase; not a declarable, stable reference.
• Manually planting a unique tag in the transcript, or keeping an external alias→ID index file — works, but it's entirely manual and lives outside the product.

Priority

High - Significant impact on productivity

Feature Category

Other

Use Case Example

Use cases

• Plan a suite-wide / multi-repo upgrade in one high-capability session, then reference that session's decisions from many separate execution sessions and across the related projects.
• Link a generated design doc back to the exact session that produced it, so future-me (or a reviewer) can trace the reasoning.
• Find "the architecture session" weeks later without relying on a vague auto-generated title.

Additional Context

Additional context / nice-to-haves

• A short, human-friendly ID format (not just a long UUID) would make verbal/written cross-reference much easier.
• Keep it consistent across surfaces — API/SDK, and CLI (claude --resume already lists IDs).
• Related: the proposed in-app feedback/issue-filing skill (#49413) and existing desktop-app requests.