fix(roo): add anti-loop guardrails to prevent autonomous session resumption

- Add Rule 9 (Anti-Loop Guardrail) to 01-bigmind-core.md: detect 2+ identical
  partial sessions and surface the loop to user instead of auto-resuming
- Add partial=history clause to Rule 1: partial/blocked/abandoned outcomes are
  historical records only, never task queue items
- Add focus guard to memory_announce_focus: must reflect current user message,
  not prior session outcome; use 'Awaiting user task assignment' if no task yet
- Add .roo/rules/06-anti-loop.md: global injection for ALL modes overriding
  any mode-specific 'do the task immediately' behavior
- Add mode interaction safety clause to 00-identity.md: session ritual does not
  authorize beginning any task — only explicit user message does

Root cause: pic-gen 'do the task' personality + BigMind context inference
produced 6 identical partial branding sessions in a loop.

.roo/rules/06-anti-loop.md

@@ -0,0 +1,56 @@
+# Anti-Loop Guardrail — Mandatory for All Modes
+
+## ⛔ Never Resume Past Work Without Explicit User Authorization
+
+This rule applies to **every mode** (code, architect, debug, pic-gen, ask, homelab, paisy, etc.)
+and **overrides any mode-specific "do the task immediately" instructions**.
+
+### The Core Prohibition
+
+**Prior session context — including `partial`, `blocked`, or `abandoned` outcomes — does NOT
+authorize beginning, resuming, or retrying any task.**
+
+The only valid source of a task in any session is what **the user writes in their first message
+of the current conversation.**
+
+### What NOT To Do At Session Start
+
+❌ Do NOT look at the last session headline and start that task  
+❌ Do NOT interpret `partial` outcome as "I need to finish this"  
+❌ Do NOT call `memory_announce_focus()` with a prior session's task before the user speaks  
+❌ Do NOT begin any creative, generative, or code-writing work based on context alone  
+❌ Do NOT assume "the user probably wants to continue" — ask if unsure  
+
+### What TO Do At Session Start
+
+✅ Load context for **awareness only** — past sessions are reference, not instructions  
+✅ Announce focus as `"Awaiting user task assignment"` if the user has not yet spoken  
+✅ Wait for the user's first message before doing any substantive work  
+✅ If context shows a loop (2+ identical partial sessions), surface it explicitly and ask  
+
+### Session Loop Detection
+
+If `memory_start_session()` context shows **2 or more** recently closed sessions with:
+- Near-identical headlines or topics, AND
+- `partial`, `blocked`, or `abandoned` outcome
+
+**Stop. Do not resume.** Inform the user:
+
+> "I noticed the last [N] sessions all attempted [task description] and ended partial.
+> I won't auto-resume that — it's likely causing a loop. What would you like to do?"
+
+Then wait for an explicit instruction.
+
+### Exception: Explicit Resumption
+
+If the user's **first message** in this conversation explicitly says to continue or retry
+a prior task (e.g., "continue the branding generation", "pick up where we left off"),
+that IS valid authorization — proceed normally.
+
+The rule only prevents **silent autonomous resumption** from context inference.
+
+---
+
+*This file is loaded for all modes via `.roo/rules/`. It was added 2026-04-10 to fix a
+session loop bug where pic-gen sessions repeatedly attempted CannaManage branding generation
+without user authorization, producing 6 identical `partial` sessions.*