feat: Phase 4 — seed identity + preference memories, lower band to 5%

3 identity memories (Antoine's role, projects, infrastructure) and
3 preference memories (no API keys, multi-model collab, action bias)
seeded on live Dalidou. These fill the identity/preference band
that was previously empty.

Lowered MEMORY_BUDGET_RATIO from 0.10 to 0.05 because the 10%
allocation squeezed project memories and retrieval chunks enough
to regress 4 harness fixtures. At 5% the band fits at most 1 short
memory — enough for the most relevant identity/preference fact
without starving the project-specific tiers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/atocore/context/builder.py

@@ -29,7 +29,7 @@ SYSTEM_PREFIX = (
 # Budget allocation (per Master Plan section 9):
 #   identity: 5%, preferences: 5%, project state: 20%, retrieval: 60%+
 PROJECT_STATE_BUDGET_RATIO = 0.20
-MEMORY_BUDGET_RATIO = 0.10  # 5% identity + 5% preference
+MEMORY_BUDGET_RATIO = 0.05  # identity + preference; lowered from 0.10 to avoid squeezing project memories and chunks
 # Project-scoped memories (project/knowledge/episodic) are the outlet
 # for the Phase 9 reflection loop on the retrieval side. Budget sits
 # between identity/preference and retrieved chunks so a reinforced