Migrate NEAR AI MCP credentials to product auth

[serrrfirat]

Summary

Port the NEAR AI MCP slice of #4176 by switching the bundled nearai-mcp manifest from a static SecretHandle to a ProductAuthAccount runtime credential source. Mirrors PR #4233's GitHub WASM migration for the MCP lane.

 runtime_credentials = [
-  { handle = "llm_nearai_api_key", audience = ..., target = ... },
+  { handle = "llm_nearai_api_key",
+    source = { type = "product_auth_account", provider = "nearai" },
+    audience = ...,
+    target = ... },
 ]

Effect on the auth flow

• The authorization layer (introduced in Migrate GitHub WASM credentials to product auth #4233) already routes ProductAuthAccount-sourced credentials through Obligation::InjectCredentialAccountOnce when credential.required is true. Flipping the manifest source field is therefore sufficient end-to-end.
• At dispatch, the obligation handler resolves the configured nearai account via RuntimeCredentialAccountResolver (ProductAuthRuntimeCredentialResolver impl), leases the access secret from the SecretStore, and stages it into RuntimeSecretInjectionStore under the llm_nearai_api_key slot.
• NearAiMcpEgressPlanner continues referencing the slot via RuntimeCredentialSource::StagedObligation { capability_id } — no planner change required.
• Reuses the unified CredentialStageError vocabulary from Wire Reborn auth consumers through staged credentials #4231 / Migrate GitHub WASM credentials to product auth #4233's alignment commit, so AuthRequired vs Backend semantics are uniform across first-party / WASM / MCP lanes.

The narrow nearai_mcp planner comment that pointed at #4176 as future work is updated to reflect that this PR closes the MCP slice.

Dependency

Stacked on #4233 (codex/github-wasm-product-auth). Merge order: #4233 must land first, since this PR depends on:

• Obligation::InjectCredentialAccountOnce (host-api)
• RuntimeCredentialAccountResolver trait + ProductAuthRuntimeCredentialResolver impl (host-runtime, composition)
• RuntimeCredentialRequirementSource::ProductAuthAccount (host-api capability schema)
• Manifest v2 parser support for source = { type = "product_auth_account", ... }

Base branch is intentionally codex/github-wasm-product-auth so the diff stays surgical. Once #4233 lands, retarget to reborn-integration and merge.

Tests

• cargo test -p ironclaw_reborn_composition local_dev_nearai_mcp_installs_and_activates_model_visible_capability — asserts source = ProductAuthAccount(provider=nearai)
• cargo test -p ironclaw_reborn_composition --lib nearai_mcp — 9/9
• cargo test -p ironclaw_reborn_composition --lib available_extensions — 7/7
• cargo test -p ironclaw_extensions --test manifest_v2_contract — 44/44 (covers parsing of the new source variant)
• cargo test -p ironclaw_authorization --test runtime_credentials_contract — 6/6 (covers ProductAuthAccount → InjectCredentialAccountOnce emission)
• cargo fmt --check clean
• cargo check -p ironclaw_reborn_composition clean

Out of scope

• Concrete NEAR AI manual-token provider client. Reborn's durable product-auth fallback (UnavailableAuthProviderClient) + manual-token submit flow already lets users create a nearai account and supply the access secret without a dedicated provider client. A first-class AuthProviderClient implementation can land as a follow-up.
• NEARAI_API_KEY env var in ironclaw_llm (LLM chat session auth). That's a separate auth surface from the MCP extension credential and is not migrated here.

Related

• Closes the MCP slice of Reborn: wire first-party, WASM, and MCP auth consumers through product-auth staged credentials #4176
• Depends on Migrate GitHub WASM credentials to product auth #4233
• Companion to Wire Reborn auth consumers through staged credentials #4231 (GSuite first-party slice)
• Background: [Reborn Cutover Blocker] Preserve brokered HTTP credential injection #3068, [codex] Implement Google OAuth refresh lifecycle #4174, Reborn: finish ProductAuth production backend parity and OAuth PKCE HA safety #4175

[gemini-code-assist]

Code Review

This pull request updates the NEAR AI MCP server configuration to source its runtime credentials from a product-auth account provider (nearai) instead of relying on an out-of-band secret store handle. It updates the manifest file, adjusts the corresponding unit tests in factory.rs to assert this new source, and updates documentation comments in nearai_mcp.rs to clarify the upstream credential resolution flow. There are no review comments, so I have no feedback to provide.