Story tracking structure: stable IDs, workflow, and features.md rewrite

[sven1103-agent]

Summary

Establishes a stable story tracking structure for the data manager project. Introduces Story IDs, a documented story lifecycle workflow, and migrates existing immunopeptidomics stories into docs/features.md as the stakeholder-facing source of truth.

Changes

docs/features.md — rewritten

• Story ID schema documented: FEAT-<SLUG>-<NN>
• All 5 immunopeptidomics stories migrated with full narrative, acceptance criteria, stable IDs, and status
• Task section removed — tasks remain GitHub-only (implementation-level)

AGENTS.md — updated

• Governance hierarchy now reflects docs/features.md as the story source of truth
• New Story ID Schema section (§0) with rules and examples
• New Story Lifecycle section (§0) documenting the draft → approved → implement flow
• Updated task rules to reference stories by stable ID
• New "Creating Stories" section (§11) for agent delegation guidance
• Key Files Quick Reference now includes docs/features.md

GitHub issues — all 10 issues updated (already applied)

Story issues (#1428–#1432):

Issue	Stable ID
#1428	FEAT-IP-MEAS-01
#1429	FEAT-IP-MEAS-02
#1430	FEAT-IP-MEAS-03
#1431	FEAT-IP-MEAS-04
#1432	FEAT-IP-MEAS-05

Task issues (#1413–#1417): Parent Story field updated to reference stories by stable ID (e.g. FEAT-IP-MEAS-01 (#1428)).

IT tasks (#1437–#1441): Comments added marking them as superseded/skipped for this feature.

Story ID Schema

FEAT-<SLUG>-<NN>

• SLUG: abbreviated identifier derived from parent Feature (e.g., IP-MEAS for FEAT-IMMUNOPEPTIDOMICS-MEASUREMENT)
• NN: sequential number, zero-padded (e.g., 01, 02)

Story Lifecycle

1. Draft — discussion/refinement in SharePoint Word doc (no stable ID, not in features.md)
2. Approved — stable ID assigned, story written into docs/features.md, GitHub issue updated
3. Implementation — Tasks reference the story by stable ID, not by GitHub issue number

What to review

• docs/features.md — story content, acceptance criteria, IDs, status
• AGENTS.md — new Story ID Schema, Story Lifecycle, and Creating Stories sections

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sven1103]

After talking to @Steffengreiner we go with this suggestion.