docs: add phased implementation plan and architecture decision records

Turns the design doc into an ordered, dependency-correct build plan (phases
0-9) with an exit criterion per phase, and records the twelve architectural
decisions it rests on as ADRs.

Decisions: single Rust binary with routed compose services; Streamable HTTP
only; per-agent bearer tokens with clientInfo as a display hint only; SQLite;
get_rules delivered via session gating; full-document rule delivery; project_id
from day one; enforcement tier scoped to Bridle-mediated actions; stable tool
list on upstream failure; OpenAI-compatible embeddings with model/dim guarding;
pattern RAG gated behind a spike; CLAUDE.md + AGENTS.md as v1 renderer targets.

Deviates from the design doc's original 1-8 ordering by moving the audit log
and multi-project schema into phase 1, building the admin API incrementally
rather than all at the Web Panel phase, downgrading vendor guardrail sourcing
to manual-first, and gating the pattern-example RAG behind a validation spike.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019RZerbsHGF9Ka3bKhCjJ9m

docs/adr/0010-openai-compatible-embeddings.md

@@ -0,0 +1,29 @@
+# ADR-0010: Generic OpenAI-compatible embeddings with model/dimension guarding
+
+**Status:** Accepted (2026-08-08)
+
+## Context
+
+The design doc specified embeddings generated locally via LM Studio on an RTX 3060. Hard-coding
+that makes the entire memory subsystem depend on one service and one GPU box being up. Separately,
+the choice of embedding model **pins the vector dimensionality** of a Qdrant collection — changing
+models silently corrupts a collection or forces a full reindex, and neither should happen by
+accident.
+
+## Decision
+
+Target a **generic OpenAI-compatible embeddings endpoint**, configured by `EMBEDDING_URL`,
+`EMBEDDING_MODEL`, and `EMBEDDING_DIM`. LM Studio, Ollama, and text-embeddings-inference all
+satisfy this.
+
+Record `{model, dim, created_at}` in each Qdrant collection's metadata. On any write, compare the
+configured model and dimension against the collection's recorded values; on mismatch, **refuse the
+write** and flag that a reindex is required.
+
+## Consequences
+
+- The 3060 is no longer a hard single point of failure; users may point at whatever they run.
+- Changing embedding models becomes a loud, explicit reindex rather than silent corruption.
+- Slightly more configuration surface than hard-coding LM Studio.
+- Bundling a small CPU embedding container as a compose profile default remains available later to
+  improve the out-of-box experience for new adopters.