feat: add provider-neutral LLM layer with secrets, budgets, recording and prompts

Phase 7 (ADR-0004). Cognitive code asks the router for a role; the
router maps roles to configured models with ordered fallbacks, applies
global and per-mind daily token budgets and a concurrency limit, records
every call (request, response, usage, latency, cost, seed, request hash)
and can serve recordings back for exact replay. Providers are raw HTTP
clients for OpenAI-compatible, Anthropic and Ollama endpoints, with
embedding support for the embed role wired into memory retrieval.

Secrets are references only: env:, file:, or enc: values encrypted with
AES-256-GCM under NOEMA_MASTER_KEY; keys are resolved at call time and
never rendered, logged or exported. Outbound HTTP refuses private and
loopback addresses at dial time unless a provider explicitly allows it,
bounds redirects and caps bodies. Provider errors are scrubbed.

Prompts are named, versioned rows with system and user templates and an
optional JSON schema; untrusted text enters only through delimited data
blocks. Six defaults are seeded and never overwritten. The UI adds the
LLM page (providers, models, role matrix, usage, errors, budgets), a
provider page with connectivity test, and a prompt manager with editor,
test runner, history, restore, clone and diff. CLI: provider, prompt.

internal/llm/prompts/defaults/narrate.tmpl

@@ -0,0 +1,18 @@
+---
+role: narrate
+description: Write the mind's concise internal narrative from its current state.
+system: |
+  You write a short first-person status note for a cognitive system, strictly from the state provided. No speculation beyond it; no claims of feelings as facts, describe state values as state.
+---
+Write at most 120 words covering: what I am doing, why, what happened recently, what I am trying to resolve, what might happen next.
+
+Workspace:
+{{range .Workspace}}- {{.}}
+{{end}}
+Recent events:
+{{range .Recent}}- {{.}}
+{{end}}
+Active goals:
+{{range .Goals}}- {{.}}
+{{end}}
+Open contradictions: {{.Contradictions}}