feat: reorganise bash scripts and add comprehensive documentation (#6)

## Summary

This PR completes the bash script restructuring and adds comprehensive documentation across all script categories.

### Bash Restructuring

- Moved cohort shell scripts (`remove_github_members.sh`, `update_github_teams.sh`) from `python/cohort/` into a new `bash/cohort/` directory
- Moved existing bash utilities (`add-keys-to-git.sh`, `fix-yubikey-perms.sh`, `list-yubikey-ssh-keys.sh`) into a new `bash/yubikey/` subdirectory
- Updated `run.sh` to support **Bash** as a third language option alongside TypeScript and Python
  - Bash scripts are run directly (no 1Password secret injection needed)
  - Category discovery and script listing works the same as for TS/Python
  - Removed dead "Root Scripts" logic that was no longer needed

### Documentation

Added `README.md` files for all script categories that were missing them:

- `bash/cohort/README.md` — cohort GitHub team management scripts
- `bash/yubikey/README.md` — YubiKey SSH key and permission utilities
- `typescript/src/crowdin/README.md` — Crowdin translation management scripts
- `typescript/src/discord/README.md` — Discord bot utility scripts
- `typescript/src/discourse/README.md` — Discourse forum management scripts
- `typescript/src/gitea/README.md` — Gitea bulk repository operation scripts
- `typescript/src/github/README.md` — GitHub API interaction scripts
- `typescript/src/music/README.md` — Music file metadata tools
- `typescript/src/s3/README.md` — S3-compatible object storage scripts
- `typescript/src/security/README.md` — Security analysis and reporting scripts
- `python/cohort/README.md` — Updated to remove moved shell scripts, fix usage commands

Also updated project-level docs:

- **`README.md`** — Corrected project structure, fixed running instructions (removed references to non-existent `make run-ts`/`make run-py` targets), added Bash prerequisites
- **`CLAUDE.md`** — Updated project overview, structure, development standards, and script-adding guides to reflect the current state of the project

✨ This PR was created with help from Hikari~ 🌸

Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Reviewed-on: #6
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

python/cohort/generate_member_files.py

@@ -1,23 +1,46 @@
+"""Generate markdown participant and leader profile files for the cohort.
+
+Reads all evaluation data files and produces two markdown files summarising
+each member's tech stack, availability, proficiency, and leadership assessment.
+
+Data files (place in data/):
+  - discord_verification.json   Discord ID verification results (from verify_discord.py)
+  - proficiency_evaluations.json  Proficiency scores (from evaluate_technical_proficiency.py)
+  - availability_analysis.json  Availability UTC blocks (from analyse_availability.py)
+  - leadership_candidates.json  List of applicants who expressed interest in leading
+  - leadership_evaluations.json  Leadership assessment scores
+
+Outputs (written to data/):
+  - participants.md  Markdown profile for each participant
+  - leaders.md       Markdown profile for each leader candidate
+
+Env vars:
+  - None
+"""
+
 import json
+from pathlib import Path
+
+DATA_DIR = Path(__file__).parent.parent.parent / "data"
 
 BLOCK_EMOJIS = {"mornings": "🌅", "afternoons": "☀️", "evenings": "🌆", "nights": "🌙"}
 
 
 def load_all_data():
     """Load all evaluation data files"""
-    with open("discord_verification.json") as f:
+    with open(DATA_DIR / "discord_verification.json") as f:
         verification = json.load(f)
 
-    with open("proficiency_evaluations.json") as f:
+    with open(DATA_DIR / "proficiency_evaluations.json") as f:
         proficiency = json.load(f)
 
-    with open("availability_analysis.json") as f:
+    with open(DATA_DIR / "availability_analysis.json") as f:
         availability = json.load(f)
 
-    with open("leadership_candidates.json") as f:
+    with open(DATA_DIR / "leadership_candidates.json") as f:
         candidates = json.load(f)
 
-    with open("leadership_evaluations.json") as f:
+    with open(DATA_DIR / "leadership_evaluations.json") as f:
         leadership = json.load(f)
 
     return verification, proficiency, availability, candidates, leadership
@@ -230,14 +253,14 @@ def main():
     participants_md = generate_participants_md(
         non_leader_ids, verified_usernames, prof_by_id, avail_by_id
     )
-    with open("participants.md", "w") as f:
+    with open(DATA_DIR / "participants.md", "w") as f:
         f.write(participants_md)
     print(f"Generated participants.md with {len(non_leader_ids)} participants")
 
     leaders_md = generate_leaders_md(
         leader_ids, verified_usernames, prof_by_id, avail_by_id, lead_by_id
     )
-    with open("leaders.md", "w") as f:
+    with open(DATA_DIR / "leaders.md", "w") as f:
         f.write(leaders_md)
     print(f"Generated leaders.md with {len(leader_ids)} leaders")