Team-scoped decisions are stored as is_global, so they still reach every project after #604 #611

Symptom

On v4.23.0, a session opened in anthropic-partnership still receives decisions of japonais-2027, career-ops-fork and founder-os, in the "Team Decisions" block of session_start and through auto_recall. #604 / #606 added the project predicate, and the predicate works. These rows pass it because they carry is_global = TRUE.

Cause

mcp_server/core/team_scope.py (ADR-0200): a deliberate write with decision content under any agent_context is marked is_global. The docstring says the intent: "The team knows WHAT was decided regardless of WHO decided it". That is visibility across agents. is_global is then read by project_scope (ADR-1080) as visibility across projects. One flag carries two meanings, and the second one defeats the predicate for exactly the memories that matter most: deliberate decisions. A host rule that requires an agent_topic on every remember makes every recorded decision cross-project.

Evidence (local PostgreSQL store, 2026-09-17, plugin 4.23.0 from the cache)

• 46,089 current non-benchmark memories, 160 with is_global, all 160 above the injection heat floor of 0.15.
• By directory_context: japonais-2027 55, empty 47, anthropic-partnership/Cortex 13, harness-comparison 13, Developments/Cortex 10, others 22. 148 of the 160 were created in August and September 2026.
• Reproduction, run from the 4.23.0 plugin directory:
  echo '{"hook_event_name":"UserPromptSubmit","prompt":"Score audit sessions completed through lance after commit","cwd":"/Users/cdeust/Developments/anthropic-partnership"}' | python3 scripts/launcher.py mcp_server.hooks.auto_recall
  injects memory 4353879, whose content starts with "HEAD 27d3ba2 japonais-2027 Score audit". Its row: is_global = t, directory_context = ''.
• session_start with the same cwd lists 4353879, 4356519 and 4353744 under "Team Decisions". 4353744 has directory_context = /Users/cdeust/Developments/japonais-2027.

Proposed direction (owner decision, needs an ADR)

Separate the two meanings. A team decision is visible to every agent of the same project: keep the project predicate and drop the agent filter for it. is_global stays reserved for knowledge the writer declared cross-project (remember-global, the content detector in global_detector.py). The 160 existing rows need a one-off reclassification: rows with a concrete directory_context lose is_global unless the global detector confirms them; the 47 rows with an empty directory_context need a rule of their own, since an empty context never matches a project root.

Acceptance

The reproduction above injects nothing from japonais-2027 in a session whose root is anthropic-partnership, while the same prompt with cwd set to japonais-2027 still injects 4353879.