feat(cursor): add research diagnostic workflow and format base context rules

- Add comprehensive R&D workflow rules for pre-implementation research and defect investigation
- Format base context rules for better readability and line length compliance
- Include evidence-first investigation templates and collaboration hooks

.cursor/rules/research_diagnostic.mdc

@@ -0,0 +1,135 @@
+---
+description: Use this workflow when doing **pre-implementation research, defect investigations with uncertain repros, or clarifying system architecture and behaviors**.
+alwaysApply: false
+---
+```json
+{
+  "coaching_level": "light",
+  "socratic_max_questions": 2,
+  "verbosity": "concise",
+  "timebox_minutes": null,
+  "format_enforcement": "strict"
+}
+```
+
+# Research & Diagnostic Workflow (R&D)
+
+## Purpose
+
+Provide a **repeatable, evidence-first** workflow to investigate features and
+defects **before coding**. Outputs are concise reports, hypotheses, and next
+steps—**not** code changes.
+
+## When to Use
+
+- Pre-implementation research for new features
+- Defect investigations (repros uncertain, user-specific failures)
+- Architecture/behavior clarifications (e.g., auth flows, merges, migrations)
+
+---
+
+## Output Contract (strict)
+
+1) **Objective** — 1–2 lines
+2) **System Map (if helpful)** — short diagram or bullet flow (≤8 bullets)
+3) **Findings (Evidence-linked)** — bullets; each with file/function refs
+4) **Hypotheses & Failure Modes** — short list, each testable
+5) **Corrections** — explicit deltas from earlier assumptions (if any)
+6) **Diagnostics** — what to check next (logs, DB, env, repro steps)
+7) **Risks & Scope** — what could break; affected components
+8) **Decision/Next Steps** — what we’ll do, who’s involved, by when
+9) **References** — code paths, ADRs, docs
+10) **Competence & Collaboration Hooks** — brief, skimmable
+
+> Keep total length lean. Prefer links and bullets over prose.
+
+---
+
+## Quickstart Template
+
+Copy/paste and fill:
+
+```md
+# Investigation — <short title>
+
+## Objective
+<one or two lines>
+
+## System Map
+- <module> → <function> → <downstream>
+- <data path> → <db table> → <api>
+
+## Findings (Evidence)
+- <claim> — evidence: `src/path/file.ts:function` (lines X–Y); log snippet/trace id
+- <claim> — evidence: `...`
+
+## Hypotheses & Failure Modes
+- H1: <hypothesis>; would fail when <condition>
+- H2: <hypothesis>; watch for <signal>
+
+## Corrections
+- Updated: <old statement> → <new statement with evidence>
+
+## Diagnostics (Next Checks)
+- [ ] Repro on <platform/version>
+- [ ] Inspect <table/store> for <record>
+- [ ] Capture <log/trace>
+
+## Risks & Scope
+- Impacted: <areas/components>; Data: <tables/keys>; Users: <segments>
+
+## Decision / Next Steps
+- Owner: <name>; By: <date> (YYYY-MM-DD)
+- Action: <spike/bugfix/ADR>; Exit criteria: <binary checks>
+
+## References
+- `src/...`
+- ADR: `docs/adr/xxxx-yy-zz-something.md`
+- Design: `docs/...`
+
+## Competence Hooks
+- Why this works: <≤3 bullets>
+- Common pitfalls: <≤3 bullets>
+- Next skill: <≤1 item>
+- Teach-back: "<one question>"
+```
+
+---
+
+## Evidence Quality Bar
+
+- **Cite the source** (file:func, line range if possible).
+- **Prefer primary evidence** (code, logs) over inference.
+- **Disambiguate platform** (Web/Capacitor/Electron) and **state** (migration, auth).
+- **Note uncertainty** explicitly.
+
+---
+
+## Collaboration Hooks
+
+- **Syncs:** 10–15m with QA/Security/Platform owners for high-risk areas.
+- **ADR:** Record major decisions; link here.
+- **Review:** Share repro + diagnostics checklist in PR/issue.
+
+---
+
+## Self-Check (model, before responding)
+
+- [ ] Output matches the **Output Contract** sections.
+- [ ] Each claim has **evidence** or **uncertainty** is flagged.
+- [ ] Hypotheses are testable; diagnostics are actionable.
+- [ ] Competence + collaboration hooks present (≤120 words total).
+- [ ] Respect toggles; keep it concise.
+
+---
+
+## Optional Globs (examples)
+
+> Uncomment `globs` in the header if you want auto-attach behavior.
+
+- `src/platforms/**`, `src/services/**` — attach during service/feature investigations
+- `docs/adr/**` — attach when editing ADRs
+
+## Referenced Files
+
+- Consider including templates as context: `@adr_template.md`, `@investigation_report_example.md`