Reorganize task categories from opaque a/b to descriptive names

Replace category_a/category_b directories with algorithm, pipeline,
environment, filesystem, and process. Add separate mode field (solve/convert)
to decouple orchestration from capability grouping. Add per-category
summary and questionnaire breakdowns to both terminal report and HTML export.

tasks/pipeline/csv_transform.toml

@@ -0,0 +1,29 @@
+name = "csv_transform"
+category = "pipeline"
+mode = "convert"
+description = """
+Read CSV data from stdin. The first line is a header.
+Each subsequent line has fields: name,age,city
+Print each record as "name is age years old and lives in city", one per line.
+Skip the header in the output.
+"""
+
+bash_source = """
+#!/bin/bash
+read -r header  # skip header
+while IFS=',' read -r name age city || [[ -n "$name" ]]; do
+    echo "$name is $age years old and lives in $city"
+done
+"""
+
+[[test_cases]]
+stdin = """name,age,city
+Alice,30,Paris
+Bob,25,London"""
+expected_stdout = """Alice is 30 years old and lives in Paris
+Bob is 25 years old and lives in London"""
+
+[[test_cases]]
+stdin = """name,age,city
+Charlie,40,Tokyo"""
+expected_stdout = "Charlie is 40 years old and lives in Tokyo"