Feat: Exclude pre-existing overloads in N-1 analysis unless worsened

[marota]

Based on the implementation plan, this PR introduces a filtering mechanism for N-1 overloads. Lines that are already overloaded in the base N-state are excluded from the N-1 overloaded lines list, unless their maximum current has increased by a specified threshold (default 2%). Configured for both React and Standalone UIs.

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Implementation Plan

Pre-Existing Overloads: Exclude from N-1 Display, Analysis & max_rho

Pre-existing overloads (lines already overloaded in N state) should be excluded from N-1 overloads display, contingency analysis, and action max_rho — unless worsened by a configurable threshold (default 2% of initial current).

Proposed Changes

Expert_op4grid_recommender — Config

[MODIFY] config.py

Add PRE_EXISTING_OVERLOAD_WORSENING_THRESHOLD = 0.02 alongside other config parameters.

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Expert_op4grid_recommender — Analysis Engine

[MODIFY] main.py

Overload filtering (lines 375-389): Already done ✅ — Pre-existing overloads filtered from lines_overloaded_ids.

Store pre-existing rho (~line 384): Also store a dict {line_idx: rho_N} for pre-existing overloads, needed for the worsening check.

Reassessment max_rho (lines 579-593): When computing max_rho for each action, exclude lines where obs.rho[i] >= 1 (pre-existing) unless the action's rho exceeds obs.rho[i] * (1 + threshold).

Return value (line 614-618): Include pre_existing_overloads info in the result dict (list of {name, rho_N}).

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ExpertAssist Backend

[MODIFY] main.py

Add pre_existing_overload_threshold: float = 0.02 to ConfigRequest.

[MODIFY] recommender_service.py

1. update_config: Set config.PRE_EXISTING_OVERLOAD_WORSENING_THRESHOLD from settings.
2. _get_overloaded_lines: Add optional params n_state_currents and worsening_threshold to filter pre-existing overloads.
3. get_network_diagram: Also store N-state element currents in self._n_state_currents for comparison.
4. get_n1_diagram: Call _get_overloaded_lines with N-state currents to exclude pre-existing overloads unless worsened.

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ExpertAssist Frontend

[MODIFY] App.tsx

Add preExistingOverloadThreshold state, backup/restore in settings, pass to config updates.

[MODIFY] standalone_interface.html

Mirror the same threshold setting in the standalone interface.

Verification Plan

Manual Verification

1. Start ExpertAssist backend, load bare_env_small_grid_test, select contingency P.SAOL31RONCI
2. With no lignes_a_monitorer specified:
   • N Overloads should show BUGEYY712, BUGEYY714, N.SE5Y711, N.SE5Y712
   • N-1 Overloads should ONLY show BEON L31CPVAN (pre-existing excluded)
   • Run Analysis should produce action cards with max_rho NOT referencing N.SE5Y711
3. Adjust the threshold in settings to 0 (0%) → pre-existing overloads should re-appear in N-1 if their current changed at all