feat: multi-tenant Phase 3 — agent target binding (AR-3)

Cargo.toml

@@ -51,7 +51,7 @@ exclude         = ["examples", "tests", "docs", "scripts"]
 default-members = ["ras-cli", "ras-daemon"]
 
 [workspace.package]
-version       = "3.3.0"
+version       = "3.4.0"
 edition       = "2024"
 rust-version  = "1.95.0"
 license       = "MIT"

docs/superpowers/plans/2026-05-30-multitenant-phase3-target-binding.md

@@ -0,0 +1,14 @@
+# Multi-Tenant Phase 3 — Agent Target Binding (AR-3)
+
+**Goal:** Agents drive an explicitly bound tab, not "the last focused tab" — removing the cross-session race. Builtins read the target from `ToolContext`; `RunAgent` can bind a target; single-user keeps the `focused_target` fallback (only in `run_step`, never in builtins).
+
+**Repo rules:** ≤200 LOC/file, no `//` comments, no `.unwrap()` in non-test code, conventional commits.
+
+## One cohesive change (interdependent — implement together)
+- `ras-tools/src/domain/registry.rs`: add `pub target: Option<TargetId>` to `ToolContext`.
+- 7 builtins (navigate, click ×2, type_text, scroll, screenshot, press_and_hold ×2): replace `let target = ctx.browser.focused_target().await?;` with `let target = ctx.target.clone().ok_or_else(|| AppError::NotFound("no active target".into()))?;`.
+- `ras-agent/src/application/run_agent.rs`: add `bound_target: Option<TargetId>` field (default None) + `with_target(mut self, t: TargetId) -> Self`.
+- `ras-agent/src/application/run_step.rs`: source target from the bound target first, else `focused_target().ok()`; pass it into `ToolContext.target`.
+- Fix the 2 test `ToolContext` construction sites to set `target`.
+
+**Scope note:** AR-3's "required target / no fallback" is satisfied at the builtin layer (no builtin calls `focused_target`). The single-user `focused_target` fallback survives only in `run_step`; the multi-tenant `SessionManager` (Phase 5) always binds, so MT never hits the fallback.