feat: implement cost report template generator with Claude session tracking (issue #119)

Comprehensive cost tracking system implementation including:

- Cost report generator with multiple formats (summary, detailed, audit)
- Full CLI integration with cost management commands
- Claude session cost tracking and estimation
- Professional markdown reports with frontmatter/contentmatter
- Automatic cost note generation for issue implementations
- Complete test coverage (33 test cases)
- Database integration with finance schema initialization

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

markitect/finance/migrations/001_create_cost_tables.sql

@@ -0,0 +1,133 @@
+-- Migration 001: Create Cost Tracking Tables
+-- Description: Initial schema for MarkiTect cost tracking system
+-- Created: 2025-10-04
+-- Issue: #110 - Cost Tracking Database Schema
+
+-- Enable foreign key constraints
+PRAGMA foreign_keys = ON;
+
+-- Cost categories table
+CREATE TABLE IF NOT EXISTS cost_categories (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name TEXT NOT NULL UNIQUE,
+    description TEXT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Cost items table (monthly recurring and one-time costs)
+CREATE TABLE IF NOT EXISTS cost_items (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    category_id INTEGER REFERENCES cost_categories(id),
+    name TEXT NOT NULL,
+    description TEXT,
+    cost_type TEXT CHECK (cost_type IN ('monthly', 'one_time')) NOT NULL,
+    amount_eur DECIMAL(10,2) NOT NULL CHECK (amount_eur >= 0),
+    currency TEXT DEFAULT 'EUR',
+    starting_from_date DATE NOT NULL,
+    ending_date DATE,
+    is_active BOOLEAN DEFAULT TRUE,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT valid_date_range CHECK (ending_date IS NULL OR ending_date >= starting_from_date),
+    CONSTRAINT active_ongoing CHECK (NOT (is_active = FALSE AND ending_date IS NULL))
+);
+
+-- Calculation periods table
+CREATE TABLE IF NOT EXISTS cost_periods (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    period_start DATE NOT NULL,
+    period_end DATE NOT NULL,
+    period_type TEXT DEFAULT 'monthly',
+    status TEXT CHECK (status IN ('open', 'calculating', 'closed')) DEFAULT 'open',
+    total_costs DECIMAL(10,2) DEFAULT 0 CHECK (total_costs >= 0),
+    active_issues_count INTEGER DEFAULT 0 CHECK (active_issues_count >= 0),
+    cost_per_issue DECIMAL(10,2) DEFAULT 0 CHECK (cost_per_issue >= 0),
+    loss_carried_forward DECIMAL(10,2) DEFAULT 0 CHECK (loss_carried_forward >= 0),
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT valid_period CHECK (period_end >= period_start),
+    CONSTRAINT unique_period UNIQUE (period_start, period_end)
+);
+
+-- Cost transactions table (audit trail)
+CREATE TABLE IF NOT EXISTS cost_transactions (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    period_id INTEGER REFERENCES cost_periods(id),
+    cost_item_id INTEGER REFERENCES cost_items(id),
+    transaction_type TEXT CHECK (transaction_type IN
+        ('cost_incurred', 'cost_allocated', 'loss_forward', 'adjustment')) NOT NULL,
+    amount_eur DECIMAL(10,2) NOT NULL,
+    issue_id INTEGER,
+    transaction_date DATE NOT NULL,
+    description TEXT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT positive_allocated_amount CHECK (
+        transaction_type != 'cost_allocated' OR amount_eur > 0
+    )
+);
+
+-- Issue cost allocations table
+CREATE TABLE IF NOT EXISTS issue_cost_allocations (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    issue_id INTEGER NOT NULL,
+    period_id INTEGER REFERENCES cost_periods(id),
+    allocated_amount DECIMAL(10,2) NOT NULL CHECK (allocated_amount > 0),
+    allocation_date DATE NOT NULL,
+    transaction_id INTEGER REFERENCES cost_transactions(id),
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT unique_issue_period UNIQUE (issue_id, period_id)
+);
+
+-- Issue activity log table
+CREATE TABLE IF NOT EXISTS issue_activity_log (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    issue_id INTEGER NOT NULL,
+    activity_type TEXT CHECK (activity_type IN
+        ('created', 'modified', 'closed', 'reopened', 'commented', 'status_changed')) NOT NULL,
+    activity_date DATE NOT NULL,
+    period_id INTEGER REFERENCES cost_periods(id),
+    activity_details TEXT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Performance indexes
+CREATE INDEX IF NOT EXISTS idx_cost_items_active ON cost_items(is_active);
+CREATE INDEX IF NOT EXISTS idx_cost_items_type ON cost_items(cost_type);
+CREATE INDEX IF NOT EXISTS idx_cost_items_dates ON cost_items(starting_from_date, ending_date);
+CREATE INDEX IF NOT EXISTS idx_cost_items_category ON cost_items(category_id);
+
+CREATE INDEX IF NOT EXISTS idx_cost_periods_status ON cost_periods(status);
+CREATE INDEX IF NOT EXISTS idx_cost_periods_dates ON cost_periods(period_start, period_end);
+
+CREATE INDEX IF NOT EXISTS idx_cost_transactions_period ON cost_transactions(period_id);
+CREATE INDEX IF NOT EXISTS idx_cost_transactions_type ON cost_transactions(transaction_type);
+CREATE INDEX IF NOT EXISTS idx_cost_transactions_issue ON cost_transactions(issue_id);
+CREATE INDEX IF NOT EXISTS idx_cost_transactions_date ON cost_transactions(transaction_date);
+
+CREATE INDEX IF NOT EXISTS idx_issue_allocations_issue ON issue_cost_allocations(issue_id);
+CREATE INDEX IF NOT EXISTS idx_issue_allocations_period ON issue_cost_allocations(period_id);
+
+CREATE INDEX IF NOT EXISTS idx_issue_activity_issue ON issue_activity_log(issue_id);
+CREATE INDEX IF NOT EXISTS idx_issue_activity_date ON issue_activity_log(activity_date);
+CREATE INDEX IF NOT EXISTS idx_issue_activity_period ON issue_activity_log(period_id);
+CREATE INDEX IF NOT EXISTS idx_issue_activity_type ON issue_activity_log(activity_type);
+
+-- Default cost categories
+INSERT OR IGNORE INTO cost_categories (name, description) VALUES
+    ('Infrastructure', 'Server hosting, cloud services, and infrastructure costs'),
+    ('Software', 'SaaS subscriptions, licenses, and software tools'),
+    ('Domain & DNS', 'Domain registration, DNS services, SSL certificates'),
+    ('Development Tools', 'IDEs, development platforms, and productivity tools'),
+    ('AI & ML Services', 'LLM APIs, AI tools, and machine learning services'),
+    ('Marketing', 'Marketing tools, analytics, and promotional services'),
+    ('Support & Maintenance', 'Support contracts, maintenance fees, and updates'),
+    ('One-time Expenses', 'Setup fees, equipment purchases, and project-specific costs');
+
+-- Example cost items from issue description (commented out for manual addition)
+-- INSERT INTO cost_items (category_id, name, description, cost_type, amount_eur, starting_from_date) VALUES
+--     (1, 'Hosteurope Server', 'Monthly server hosting', 'monthly', 10.00, '2025-01-01'),
+--     (2, 'Bubble.io Plan', 'No-code platform subscription', 'monthly', 32.00, '2025-01-01'),
+--     (3, 'Coulomb.social Domain', 'Domain registration and hosting', 'monthly', 5.00, '2025-01-01'),
+--     (4, 'Claude Code Plan', 'AI coding assistant subscription', 'monthly', 20.00, '2025-01-01'),
+--     (5, 'Gemini Plan', 'LLM API for specification support', 'monthly', 20.00, '2025-01-01');