feat: add Category metadata and auto-generated project table

[thxtech]

Summary

• Added Category field to all 100 OSS report READMEs (e.g., Database, Web Framework, Monitoring, etc.)
• Added Reports section with a sorted project table (by Category, then name) to root README
• Created scripts/add-category.sh for bulk Category insertion and scripts/generate-table.sh for table regeneration

Test plan

• Verify scripts/generate-table.sh runs without errors and produces 100 rows
• Verify each oss/*/README.md has a | Category | row in the metadata table
• Verify root README table links resolve correctly to each report

🤖 Generated with Claude Code

[claude]

Code review

Found 1 issue:

scripts/add-category.sh:107 - sed -i '' portability bug

The sed -i '' syntax on line 107 uses BSD sed (macOS) syntax that is incompatible with GNU sed used on Linux.

The problem:

• On macOS BSD sed: sed -i '' means "edit in-place with no backup"
• On GNU sed (Linux): sed -i '' interprets '' as the sed script (empty string), not a backup extension, causing the command to fail

Since this repository's CI environment is Linux (Linux 6.11.0-1018-azure), this script will fail when executed.

Code reference:

ossarch/scripts/add-category.sh

Lines 106 to 110 in 337917b

	if grep -q "^| Primary Language |" "$readme"; then
	sed -i '' "/^| Primary Language |/a\\
	| Category | ${category} |
	" "$readme"
	count=$((count + 1))

Suggested fix:
For GNU sed, use sed -i (without the empty string argument) for in-place editing with no backup.