feat(llm): add nomic-embed-text-v1.5-Q4_K_M to astro-orbiter router

OpenViking Phase 1b (t_34b96e83) — Ryan-approved implementation.

Changes:
- roles/llm-inference-multimodel/templates/llama-server-router-preset.ini.j2:
  Add [nomic-embed-text-v1.5] section with embedding=true, n-gpu-layers=99,
  ctx-size=8192, load-on-startup=true, sleep-idle-seconds=-1. No flash-attn
  or KV cache params (embedding models use bidirectional forward pass, not
  autoregressive KV cache). Var: llm_router_nomic_ctx_size.

- roles/llm-inference-multimodel/defaults/main.yml:
  Add llm_router_nomic_ctx_size: 8192.

- host_vars/astro-orbiter/vars.yml:
  Add nomic-embed-text-v1.5-Q4_K_M.gguf to llm_staged_models list
  (size_bytes: 84106624, source: nomic-ai/nomic-embed-text-v1.5-GGUF).
  Update VRAM note to reflect 5 registered models (nomic adds ~84MB,
  negligible given sleep-idle-seconds=-1 / load-on-startup=true pinning).

- playbooks/day2_add_nomic_embed.yml:
  New day2 playbook following the coder-alias pattern:
  Phase 1: idempotent GGUF download (exact size check)
  Phase 2: redeploy preset INI
  Phase 3: redeploy + restart systemd unit
  Phase 4: /v1/models gate (all 5 models present)
  Phase 5: /v1/embeddings smoke test (vector returned, not empty)

VRAM: ~84MB, always pinned. No impact on generative model LRU behavior.
peter-parker Helm values already point at :8002 for the embedding endpoint.

ansible/roles/llm-inference-multimodel/defaults/main.yml

@@ -160,3 +160,8 @@ llm_router_phi_flash_attn: "{{ llm_router_flash_attn }}"
 llm_router_coder_ctx_size: 16384
 llm_router_coder_flash_attn: "true"
 llm_router_preset_path: /opt/llama-server-router-preset.ini
+# nomic-embed-text-v1.5: embedding model, ctx-size=8192 per task t_34b96e83
+# No flash_attn or KV cache params — embedding models use bidirectional forward pass,
+# not autoregressive KV cache. load-on-startup=true / sleep-idle-seconds=-1 keep it
+# always warm at negligible VRAM cost (~84MB).
+llm_router_nomic_ctx_size: 8192

ansible/roles/llm-inference-multimodel/templates/llama-server-router-preset.ini.j2

@@ -40,6 +40,14 @@
 ; Hermes custom_providers routing — see role README / deployment report for
 ; the alias-naming ambiguity flag (Ryan's pasted TOML used different alias
 ; strings: "llama-3.1-8b" / "phi-3.5-mini").
+;
+; UPDATED (t_34b96e83, 2026-08-13, per Ryan approval): Added nomic-embed-text-v1.5
+; embedding model. Embedding models fold cleanly into the router preset via
+; embedding=true. No alias needed — clients call it by section name.
+; VRAM estimate ~90MB (negligible). sleep-idle-seconds=-1 keeps it always loaded
+; since embedding calls are latency-sensitive and it costs near-nothing to hold.
+; load-on-startup=true ensures the embedding endpoint is warm at boot without
+; waiting for the first request. — War Machine.
 ; ------------------------------------------------------------------------------
 
 ; --- Production model: Qwen3.6-35B-A3B-UD-Q4_K_S ----------------------------
@@ -124,3 +132,25 @@ cache-type-v = {{ llm_router_cache_type_v }}
 batch-size   = {{ llm_router_batch_size }}
 ubatch-size  = {{ llm_router_ubatch_size }}
 parallel     = {{ llm_router_parallel }}
+
+; --- Embedding model: nomic-embed-text-v1.5 ----------------------------------
+; Primary model ID: nomic-embed-text-v1.5 (section name / client-visible ID)
+; ~84MB GGUF — negligible VRAM, always-loaded. Embedding endpoint: /v1/embeddings.
+; embedding=true: required to expose /v1/embeddings and embed the model (not chat).
+; n-gpu-layers=99: GPU offload all layers (tiny model, no reason to leave on CPU).
+; ctx-size=8192: per task spec (OpenViking Phase 1b, t_34b96e83).
+; load-on-startup=true: warm at boot — embedding callers (peter-parker) are
+;   latency-sensitive; no cold-load wait on first request.
+; sleep-idle-seconds=-1: never evict — ~84MB is negligible, always keep hot.
+; NO flash-attn, NO KV cache params: embedding models use a different forward
+;   pass (bidirectional, no autoregressive KV cache). These keys are irrelevant
+;   for embedding inference and may be silently ignored or cause warnings; omit.
+; Source: nomic-ai/nomic-embed-text-v1.5-GGUF (public, no auth needed)
+; Added 2026-08-13 (t_34b96e83) — War Machine.
+[nomic-embed-text-v1.5]
+model              = {{ llm_models_dir }}/nomic-embed-text-v1.5-Q4_K_M.gguf
+embedding          = true
+n-gpu-layers       = {{ llm_router_gpu_layers }}
+ctx-size           = {{ llm_router_nomic_ctx_size }}
+load-on-startup    = true
+sleep-idle-seconds = -1