PlanForceBot consults the state-less ForcePlanBlockers overload: it cannot see apc_owns_it / forcing_failed_on_this_plan / already_forced before an automatic force #3654

Summary

#3652 taught the force-plan verdict to read the store's forcing and automatic-plan-correction state at read time: FactRemediation.ForcePlanBlockers(ForcePlanTarget, ForcePlanTargetState?) adds apc_owns_it, already_forced, forcing_failed_on_this_plan, apc_withdrew_it and apc_resolved_differently, and both SKUs' MCP surfaces pass a per-target ForcePlanTargetState read by ForcePlanTargetStateReader (Lite, DuckDB) / DarlingForcePlanTargetStateReader (Darling, Postgres).

PlanForceBot (Darling/PerformanceMonitor.Darling.Service/PlanForceBot.cs ~157) still calls the ORIGINAL one-argument overload — the two #2138 blockers only — and hands that list to ForcePlanBotPolicy.Evaluate. So the automatic bot's gate has exactly the gap #3652 closed on the advisory surface: it would judge a plan APC is mid-verification on, a plan whose force_failure_count is already climbing, or a plan already forced by hand, as unblocked. The bot is dry-run-gated today (write-gate 2, V107), which is why this is a follow-up rather than part of #3652; it must not go live without this.

Fix shape

• PlanForceBot reads the state for its candidate targets through DarlingForcePlanTargetStateReader.ReadAsync (it has the NpgsqlDataSource) and calls the two-argument overload; the journal row records the blocker names AND the evidence strings (ForcePlanBlocker.Evidence), so a Blocked decision is auditable against the snapshot it was made on.
• When the state read fails, the bot treats it as a blocker of its own (state_unavailable) — the advisory surface can say "unknown" and let a human decide; an automatic actor cannot.
• ForcePlanBotPolicy stays pure; it already takes the blocker list as data.
• Pin: PlanForceBotTests gains the five Force-plan remediation reports 'eligible, no blockers' for plans automatic plan correction already owns, has already failed to force, or has withdrawn — five for five on one incident #3652 shapes and the unavailable-state arm; ForcePlanTargetStateTests.ThePlanForceBotsGate_IsTheOriginalOverload_AndStillAgreesWithTheTargetHalf currently pins the GAP (so it is a test, not a surprise) and flips when this lands.

Related: #3652 (the advisory-surface fix), #2138 (the bot), #3579 (Forced Plan Failing is the alert side of force_failure_count).