fix: migrate Claude model files to current API IDs (opus-5, sonnet-5, haiku-4.5)

Bug 57d8a047-d26d-47ce-ae6f-bc5cb98fef0e: Opus-tier tasks 404'd because
models/claude-opus-4.yaml pinned default_flags.model to "claude-opus-4-5",
a retired ID. models/claude-sonnet-4.yaml was pinned to a dated snapshot
("claude-sonnet-4-20250514") with the same problem.

Slug strategy: the registry slug (filename / RegistryEntry.name) doubles
as the literal --model argument on the workflow-template pass-through path
(task-templates/workflow/*.yaml `model:` field -> compiler WF-COMP-18 ->
payload.runtime.model -> entrypoint/runners/claude.py `--model`), which has
no translation step through this file's default_flags. So rather than
patch default_flags.model in place (leaving the slug stale and the
pass-through bug latent), rename the slug to match the current API ID:

- models/claude-opus-4.yaml, model-registry/claude-opus-4.yaml
  -> claude-opus-5.yaml (name/endpoint/default_flags.model: claude-opus-5)
- models/claude-sonnet-4.yaml, model-registry/claude-sonnet-4.yaml
  -> claude-sonnet-5.yaml (claude-sonnet-5)
- model-registry/claude-haiku-4.yaml -> claude-haiku-4-5.yaml
  (claude-haiku-4-5); added the previously-missing models/claude-haiku-4-5.yaml
  so the claude runner can actually resolve this endpoint
- model-registry/harness-roles.yaml, model-registry/tiers.yaml,
  workflows/smart-agent.yaml, task-templates/workflow/{spec,plan}-review-loop@1.yaml:
  updated every claude-opus-4 / claude-sonnet-4 / claude-haiku-4 reference
  to the new slugs
- models/openrouter-sonnet.yaml: dated snapshot "claude-sonnet-4-20250514"
  -> "claude-sonnet-5" (third-party router proxying the same retired ID)
- refreshed cost_per_1k_tokens on the three renamed registry entries to
  current published pricing

Claude-Session: https://claude.ai/code/session_015nXvGNNNixJPFwZKZHNyha

task-templates/workflow/plan-review-loop@1.yaml

@@ -19,7 +19,7 @@ nodes:
   - id: review-opus
     kind: agent
     role: plan-review  # M36 v0.6 (bug 69370eda fix)
-    model: claude-opus-4
+    model: claude-opus-5
     runtime_env:
       AGENT_REPO_URL: "git@gitea.oreillyit.nz-ai-enablement:skynet/agent-runtimes-agents.git"
       AGENT_BRANCH: "task/${item.uuid}"
@@ -93,7 +93,7 @@ nodes:
   - id: judge-haiku
     kind: agent
     role: plan-review
-    model: claude-haiku-4
+    model: claude-haiku-4-5
     depends_on: [improve-sonnet]
     runtime_env:
       AGENT_REPO_URL: "git@gitea.oreillyit.nz-ai-enablement:skynet/agent-runtimes-agents.git"

task-templates/workflow/spec-review-loop@1.yaml

@@ -24,7 +24,7 @@ nodes:
     role: spec-review  # M36 v0.6 (bug 69370eda fix): per-node role replaces
                        # the ungrounded top-level `runtime: review-loop-repo`.
                        # Harness resolution: (role, model) → composite.
-    model: claude-opus-4
+    model: claude-opus-5
     runtime_env:
       AGENT_REPO_URL: "git@gitea.oreillyit.nz-ai-enablement:skynet/agent-runtimes-agents.git"
       AGENT_BRANCH: "spec/${item.uuid}"
@@ -104,7 +104,7 @@ nodes:
   - id: judge-haiku
     kind: agent
     role: spec-review
-    model: claude-haiku-4
+    model: claude-haiku-4-5
     depends_on: [improve-sonnet]
     runtime_env:
       AGENT_REPO_URL: "git@gitea.oreillyit.nz-ai-enablement:skynet/agent-runtimes-agents.git"