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/log_parser.toml

@@ -0,0 +1,34 @@
+name = "log_parser"
+category = "pipeline"
+mode = "convert"
+description = """
+Read log lines from stdin. Each line has the format: "LEVEL: message"
+where LEVEL is one of ERROR, WARN, INFO.
+Count occurrences of each level and print a summary sorted by level name.
+Format: "LEVEL: count"
+"""
+
+bash_source = """
+#!/bin/bash
+while IFS= read -r line || [[ -n "$line" ]]; do
+    echo "${line%%:*}"
+done | sort | uniq -c | while read -r count level; do
+    echo "$level: $count"
+done
+"""
+
+[[test_cases]]
+stdin = """ERROR: disk full
+INFO: started
+WARN: low memory
+ERROR: timeout
+INFO: completed"""
+expected_stdout = """ERROR: 2
+INFO: 2
+WARN: 1"""
+
+[[test_cases]]
+stdin = """INFO: boot
+INFO: ready
+INFO: shutdown"""
+expected_stdout = "INFO: 3"