Feat/plot educacao

[rainasouza]

Description

This PR implements the education chart for the automatic reporting system.

What was done

• New education plot module (plotting/educacao.py): generates grafico_cor_faixa_etaria_*.png — grouped bars comparing illiteracy rates by color/race (Amarela, Branca, Indígena, Parda, Preta) across six age brackets (15–19, 20–29, 30–39, 40–49, 50–59, 60+).
• Report integration (reports.py): hooks the chart into graficos_por_placeholder["grafico_cor_faixa_etaria"] for the educacao macrotema.
• Dynamic y-axis: the previous hardcoded limit (0–35%) truncated bars above 35%. The axis is now computed from the data (rounded up to the nearest ten), so charts always fit their data.
• Larger font: tick labels and legend bumped from 8 to 9 for better readability.
  - Docs-driven captions (utils/renderer.py): Removed the auto-generated duplicate caption (Figura N - Cor e faixa etária).
• The figure caption now comes straight from the docs text (e.g., Figura X – Taxa de analfabetismo por cor ou raça ...).
• The X placeholder in the docs is replaced by an automatic sequential counter (Figura 1, Figura 2, ...), reset per report; any letter (or &) is now accepted as the placeholder.
• Cleanup: removed dead code (plotting.py, generate_report.py, stale CSVs).
  Files changed
• plotting/educacao.py (new)
• reports.py
• utils/renderer.py
• removed: plotting.py, generate_report.py, demografia.csv, educacao.csv