Normalize KbAlertingService alert sender identity

Context

Follow-up from PR #11804 review after the #11797 swarm-heartbeat identity normalization fix merged. #11804 correctly centralized normalizeAgentIdentityNodeId() in ai/scripts/resumeHarness.mjs and used it for the folded heartbeat lane. The review surfaced one adjacent consumer of the same environment variable class: ai/daemons/KbAlertingService.mjs reads process.env.NEO_AGENT_IDENTITY directly when dispatching A2A alerts.

Verified evidence before filing:

• PR #11804 is merged and intentionally left #11797 open for L4 post-merge validation.
• rg -n "NEO_AGENT_IDENTITY|DEFAULT_SENDER|normalizeAgentIdentityNodeId" ai/daemons/KbAlertingService.mjs ai/scripts/resumeHarness.mjs test/playwright/unit/ai/daemons test/playwright/unit/ai/scripts shows KbAlertingService.mjs:318 consumes process.env.NEO_AGENT_IDENTITY || DEFAULT_SENDER raw.
• The same command shows normalizeAgentIdentityNodeId() is exported from ai/scripts/resumeHarness.mjs and already unit-covered for neo-opus-ada -> @neo-opus-ada, prefixed identities, and whitespace trimming.
• Duplicate sweep: ask_knowledge_base("KbAlertingService NEO_AGENT_IDENTITY normalization ticket duplicate", type="ticket") found related identity-binding tickets but no KbAlertingService duplicate; exact grep over resources/content/issues / resources/content/discussions found KbAlertingService history (#11642) and NEO_AGENT_IDENTITY history, but no equivalent open follow-up. Live gh issue list --search "KbAlertingService is:issue is:open repo:neomjs/neo" returned [].

The Problem

NEO_AGENT_IDENTITY can be configured in GitHub-login form (neo-opus-ada) while A2A identity surfaces are graph node ids (@neo-opus-ada). #11804 fixed this for SwarmHeartbeatService, but KbAlertingService still passes the raw env-var value as its alert sender.

If the env var is unprefixed, KB alert messages can be emitted from a sender value that does not match the AgentIdentity node-id shape used elsewhere. That creates avoidable identity drift in A2A alert telemetry and can force future agents to re-debug the same normalization class from a different daemon.

The Architectural Reality

Relevant surfaces:

This is not a new identity subsystem and not a broader NEO_AGENT_IDENTITY audit. It is a single known consumer using the same normalization primitive that already shipped for #11797.

The Fix

Normalize the alert sender at the KbAlertingService boundary before calling A2A dispatch:

1. Reuse normalizeAgentIdentityNodeId() rather than adding a second normalizer.
2. Preserve DEFAULT_SENDER = '@system' fallback behavior when NEO_AGENT_IDENTITY is unset.
3. Add focused KbAlertingService unit coverage proving an unprefixed NEO_AGENT_IDENTITY produces a prefixed sender in the outgoing A2A payload.
4. Keep this scoped to the alert sender field; do not alter alert rule evaluation, pulse scheduling, or target pre-check semantics.

Contract Ledger Matrix

Decision Record Impact

none. This is aligned with the existing AgentIdentity binding convention and the #11804 normalization boundary. No ADR amendment needed.

Acceptance Criteria

• AC1 — KbAlertingService normalizes process.env.NEO_AGENT_IDENTITY through the existing normalizeAgentIdentityNodeId() helper before using it as an A2A alert sender.
• AC2 — Existing DEFAULT_SENDER = '@system' fallback remains unchanged when NEO_AGENT_IDENTITY is unset.
• AC3 — Unit coverage proves unprefixed env input (neo-opus-ada or equivalent) produces a prefixed sender in the dispatched A2A alert payload.
• AC4 — Unit coverage or existing helper tests continue proving already-prefixed identities are preserved.
• AC5 — No changes to alert-rule evaluation, target pre-check behavior, pulse scheduling, or KB telemetry schema are bundled.

Out of Scope

• Closing #11797; that ticket still needs L4 post-merge heartbeat wake validation.
• Auditing every historical NEO_AGENT_IDENTITY consumer.
• Refactoring normalizeAgentIdentityNodeId() into a new utility module.
• Changing A2A permission semantics or sender validation.

Avoided Traps

Related

• PR #11804 — fix(ai): normalize swarm heartbeat identity (#11797).
• Issue #11797 — still owns L4 post-merge heartbeat validation.
• Issue #11642 — KbAlertingService implementation history.

Origin Session ID: d60db68f-8ff0-48a6-b168-237ca9dca2a0

Handoff Retrieval Hints:

• query_raw_memories("KbAlertingService raw NEO_AGENT_IDENTITY normalizeAgentIdentityNodeId #11804")
• rg -n "NEO_AGENT_IDENTITY|DEFAULT_SENDER|normalizeAgentIdentityNodeId" ai/daemons/KbAlertingService.mjs ai/scripts/resumeHarness.mjs test/playwright/unit/ai/daemons test/playwright/unit/ai/scripts