[PPTX] Slides 3-6: Thesis, Financials, Valuation, Price Chart slide implementations

[DogInfantry]

Part of epic: #32
Depends on: #42 (cover + exec summary must exist first)

Slide 3 — Investment Thesis

• GS_BLUE header bar with white "Investment Thesis" title
• 3 bullet points, each max 20 words, sourced from commentary.py
• Each bullet has: bold 1-line claim + 2-line supporting evidence in lighter text
• Left accent bar in GS_GOLD for visual hierarchy

Slide 4 — Financial Summary

• 5-column table: Metric | FY-2 | FY-1 | FY0 (actual) | FY+1E | FY+2E
• Rows: Revenue, Gross Profit, EBITDA, EBIT, Net Income, EPS, FCF
• Header row in GS_BLUE with white text
• Alternating row shading (white / LIGHT_GREY)
• Growth % shown as small secondary text below each value

Slide 5 — Valuation

• Left half: DCF summary table (WACC, terminal growth, implied TP)
• Right half: Peer multiples table (P/E, EV/EBITDA, EV/Sales vs peer avg)
• Target price bridge: current price → DCF → peer CCA → blended TP

Slide 6 — Price Chart

• Embed existing 12-month price chart PNG from charts.py (left 60% of slide)
• Right 40%: 4 key stats (YTD return, 52W high/low, beta, avg volume)
• Index overlay label showing vs S&P 500 performance

Acceptance Criteria

• All 4 slides (_add_thesis_slide, _add_financials_slide, _add_valuation_slide, _add_price_chart_slide) implemented
• Financial table populates from existing pipeline JSON fields
• Price chart PNG embedded as image (not as PowerPoint native chart)
• All text editable in PowerPoint
• No content overflows slide boundaries at 1920x1080