phase 0 setup: agent defs cleaned, AGENTS.md, initial phase-0.md draft

- sdd_process.md + coordinator.md: stale @alkdev/alkblobs name from the
  copy fixed to @alkdev/alkstore
- implementation-specialist.md: copied alkcall-family conventions
  (OperationEnv, vendored core types, BAST/wire formats) replaced with
  crate-neutral rules + an ADR-escalation rule
- code-reviewer.md: stale tls/iroh/acme feature list removed; anyhow
  posture corrected; db-specific review checks added
- AGENTS.md: phase-0 posture (no crate yet, no README, POC/discipline
  conventions, OQ-ST-NN register, reference checkouts)
- docs/research/phase-0.md: initial draft — vision, prior art (honker,
  pgboss-rs read incl. verified pgboss-rs LISTEN/NOTIFY absence), open
  questions OQ-ST-01..08, phase 0 plan

.opencode/agents/coordinator.md

@@ -191,7 +191,7 @@ also include:
 Example prompt template:
 
 ```
-You are an implementation specialist for the @alkdev/alkblobs project.
+You are an implementation specialist for the @alkdev/alkstore project.
 
 Your task: {{task}}
 
@@ -204,7 +204,7 @@ Your task: {{task}}
 7. Push: git push origin $(git branch --show-current)
 8. Notify: worktree({action: "notify", args: {message: "Task completed: {{task}}. <brief summary>", level: "info"}})
 
-Key project constraints (@alkdev/alkblobs):
+Key project constraints (@alkdev/alkstore):
 - Rust: use cargo build, cargo clippy, cargo fmt, cargo test
 - No comments in code
 - thiserror for error types