Separate stable agent identity from mutable presentation

[schickling-assistant]

Summary

• preserve the positional Agent Spec identity as the sole stable routing, authorization, task, state, and lifecycle key
• add optional bounded name and description declaration fields across KDL, TOML, JSON, roster output, and compact eval lowering
• add constrained source-preserving st2 rename / st2 describe KDL authoring with catalog locking, stale-source detection, Nix refusal, and self/descendant admission
• reconcile presentation in place through exact-ID atomic PTY metadata patches; primary names map to native displayName, while every managed PTY gets the versioned actor/description tag snapshot
• make catalog-derived message routing accept declared stable Agent Spec identities only, so a mutable display name cannot create or address undeclared catalog state
• keep explicit --root as the low-level eval transport boundary: declared identities resolve to native resource boxes first, while an absent exact id addresses a flat mailbox such as the eval-owned requester
• pin the PTY prerequisite to compoundingtech/pty@4c67fb51 (draft feat: add transactional catalog bootstrap #142, stacked on duplicate-display draft fix(eval): scope external requester inbox authority #139)

Stable-ID rename and compatibility aliases are intentionally absent. The retired sibling name file is ignored. Current activity is intentionally outside this schema.

Refs #128.
Refs #127.
Depends on compoundingtech/pty#142 and compoundingtech/pty#139.

Verification

• cargo check --workspace --tests
• exact schema, authoring, CLI, reconcile, spawn, metadata-payload, and routing-mode tests
• eval-found negative: catalog-backed send to Shared Worker is rejected before creating a flat directory; send/list by stable id still uses the native declared inbox
• explicit-root eval continuity: declared canonical inboxes and the flat requester mailbox both work without display-name resolution
• live exact-PTY continuity: set/change/clear preserved stable ID, PID, and createdAt; effective changes emitted one atomic event, a no-op emitted none, and retirement still tore down the task
• focused follow-up suites: message_cli 7/7, message 5/5, canonical-agent eval filter 6/6 across the initial run plus exact retry of one post-completion PTY-list timeout
• CARGO_BUILD_JOBS=4 cargo test --all-targets --all-features -- --test-threads=4 with PATH pinned to PTY 4c67fb51: green
• git diff --check
• zero deliberate retired-activity-field surface in schema/API/CLI/roster/tags/VRS

devenv tasks run check:quick is unavailable because this repository has no devenv.nix. The README clippy command remains inherited-red with 161 pre-existing warnings promoted to errors; the one new warning found in this change was fixed. The flake explicitly does not gate clippy or rustfmt.

The VRS decision remains draft and requires Nathan's approval.

[schickling-assistant]

Superseded by #136, which is restacked on current main, pins final PTY #142 head 706e4f5, closes the validation and lifecycle-proof gaps, and preserves the accepted narrow authoring-lock design.