fix: Fase 0 — Estabilitat del Fork (7 stability patches)

[jaumemir]

Summary

Hardening pass resolving 7 stability issues identified in the enterprise roadmap (2026-04-26):

• PR fix: prevent action data loss from partial line reads in _read_action_log 666ghj/MiroFish#460 equiv — Fix _read_action_log partial JSONL reads; safe_position only advances on complete lines ending with \n
• PR fix: add max_items limit to fetch_all_edges to prevent unbounded memory growth 666ghj/MiroFish#553 equiv — Cap get_all_edges to 5000 items with Cypher LIMIT to prevent unbounded RAM growth on large graphs
• PR Improve database resource management and IPC input handling 666ghj/MiroFish#578 equiv — Guarantee SQLite connection close with finally block; guard agent_id against None
• PR fix: strip fabricated tool_result blocks to prevent LLM hallucination 666ghj/MiroFish#559 equiv — Strip fabricated <tool_result> blocks from LLM responses to prevent ReAct hallucination loops
• PR fix: handle string attributes in graph ontology to prevent TypeError crash 666ghj/MiroFish#581 equiv — Normalize string attributes in LLM-generated ontology to prevent TypeError: string indices must be integers
• New — Persist active_task_id to project.json; MainView.vue reconnects polling after browser refresh
• New — Persist upload simulationRequirement to sessionStorage; friendly redirect error when files are lost on refresh

Test plan

• cd backend && uv run pytest tests/ -v — 10 new tests green (1 pre-existing env failure acceptable)
• cd frontend && npm run build — no errors
• Manual: start a graph build → refresh browser mid-build → should show "Reconnecting to active task…" and resume polling
• Manual: select files on Home → refresh MainView before files upload → should show friendly error and redirect to Home after 3s
• Manual: start a simulation with large document → server RAM should not spike unboundedly