Task 213: Complete ADR-015 考察→考証 rename (missed items from Task 182)

Status: DONE

Description

Task 182 applied the rename to templates/reports/build but missed several project-level files.

This task completes the remaining items.

Remaining items

• [ ] CLAUDE.md line 7: "SOLAR LINE 考察" → "SOLAR LINE 考証"
• [ ] DESIGN.md line 1: "# SOLAR LINE 考察" → "# SOLAR LINE 考証"
• [ ] README.md: title, description, link text
• [ ] adr/README.md: description text + ADR-015 status Proposed→Accepted
• [ ] ts/package.json: description field
• [ ] ts/e2e/reports.spec.ts: comment
• [ ] Memory file update

Intentionally preserved (per Task 182)

• Generic "### 考察" section headers (analytical sense)
• "ヤコビアン的考察", "軌道力学的考察" (generic analytical usage)
• Human directive verbatim quotes
• ADR-015 body text (historical discussion of the naming)
• ideas/naming_kousatsu_vs_koushou.md (historical)