feat(openshell-core): add MCP route observation state

[shiju-nv]

Summary

Add the OpenShell-owned primitives for representing MCP route identity, observation outcomes, and epoch-aware readiness state. This establishes a redacted state-machine boundary that later gateway and runtime PRs can consume without coupling lifecycle readiness to route evidence.

Related Issue

Related to #3205

This is the first PR in a three-PR stack. It establishes the core layer but does not complete the public gateway or runtime behavior, so the final runtime PR uses Closes #3205 after the dependencies land.

Changes

• Derive opaque SHA-256 route subjects from normalized host, canonical path, and the sorted, deduplicated effective port set.
• Define typed redacted outcomes for reachable, policy-denied, credential, TLS, transport, upstream-rejection, and unobserved states.
• Add a bounded, non-blocking observation channel and an epoch-aware tracker that coalesces observations without affecting sandbox lifecycle phase.
• Cover canonicalization, deduplication, multi-port identity, epoch reset, timestamp, and bounded-channel behavior with unit tests.
• Update both standalone example lockfiles so their openshell-core dependency graphs include the new hashing and TLS dependencies and mise run pre-commit leaves the worktree clean.

Testing

• mise run pre-commit passes
• Unit tests added/updated
• E2E tests added/updated (not applicable to this core-only state-machine boundary)

Checklist

• Follows Conventional Commits
• Commits are signed off (DCO)
• Architecture docs updated (not applicable to this internal primitive boundary; public semantics are documented in the dependent gateway PR)