feat(citadel): cover letter, and fix SW-1 scope traps in two more bundles

Cover letter: 1 page, 270 words, 3 paragraphs, validator PASS. Carries
the one thing the resume structurally cannot - why a Swisscom data
engineer credibly wants a research-platform seat at a market maker,
which against an ex-FAANG field is the main differentiator.

Deliberately uses no external hooks. cl_reference.md says to omit an
unnecessary hook rather than spend words proving company familiarity, so
the only hook is the JD's own language, scraped verbatim and first-party.
No named executives: nothing to verify, and nothing that reads as
name-dropping. The letter also states the R1 gap plainly rather than
hiding it, because a technical reviewer will find it in the first
question anyway and owning it is stronger than being caught by it.
PP-1 appears with its personal-project label and an explicit "I make no
claims for its results".

Separately, loading the bundles for this letter surfaced two live scope
traps. The 2026-08-21 correction that fixed the SW-1 violation in
bundle_data_engineer.md ended with "check the other four bundles for the
same pattern". That sweep was never done, and two of them carried it:

  bundle_data_platform.md - the S5 cover-letter hook read "migrating
  Swisscom's legacy ETL stack to a cloud-native AWS platform", and its
  narrative thread said "migrating an entire ETL infrastructure". Both
  pair a full-ownership framing with a company-scale object, which
  claims.json SW-1 forbids outright.

  bundle_ml_ai_engineer.md - the SW-1 reframing row read "Built
  cloud-native data infrastructure on AWS ... the scalable data layer",
  which is both a full-ownership verb on an org-scale object and an
  unverified scale claim.

Both rewritten to the scoped form with inline scope warnings, matching
the data_engineer fix. bundle_analytics_engineer.md and
bundle_semiconductor.md were checked and are clean.

These were loaded traps: any future cover letter built from either
bundle would have started from a sentence claims.json forbids.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MHtzyTKBcg6BWhD5qFegtK

output/CitadelSecurities_PlatformEngineer/e2e_citadel_securities_platform_engineer_cover_letter.tex

@@ -0,0 +1,57 @@
+% Citadel Securities — Platform Engineer, Research Platform Engineering (Zurich)
+% Cover Letter Decision: YES — domain transition needs explaining; the resume can carry PP-1
+% only as a compact block and cannot show why a Swisscom data engineer wants this seat.
+% Industry format per cl_reference.md: 3 short paragraphs, 200--300 words.
+% Hooks: JD text only (first-party, scraped verbatim). No named executives — cl_reference.md
+% says omit an unnecessary hook rather than spend words proving company familiarity.
+% Every claim traceable to the resume. PP-1: no performance figure, labelled personal.
+
+\documentclass[11pt,a4paper]{article}
+\usepackage[utf8]{inputenc}
+\usepackage[T1]{fontenc}
+\usepackage{lmodern}
+\usepackage[a4paper,left=0.85in,right=0.85in,top=0.7in,bottom=0.7in]{geometry}
+\usepackage{parskip}
+\usepackage{xcolor}
+\usepackage{hyperref}
+\hypersetup{hidelinks}
+\pagestyle{empty}
+\setlength{\parindent}{0pt}
+
+\begin{document}
+
+{\Large\bfseries Dennis Thiessen, M.Eng.}\par
+Bern, Switzerland $\vert$
+\href{mailto:dennis@thiessen.io}{dennis@thiessen.io} $\vert$ +41 795 955 585 $\vert$
+\href{https://linkedin.com/in/dennis-thiessen}{LinkedIn}
+
+\vspace{1.5em}
+Research Platform Engineering\\
+Citadel Securities\\
+Zurich, Switzerland
+
+\vspace{1em}
+26 August 2026
+
+\vspace{1em}
+\textbf{Application for Platform Engineer, Research Platform Engineering}
+
+\vspace{0.8em}
+Dear Hiring Team,
+
+The posting describes data systems for ingestion, transformation, storage and lifecycle management of large datasets, built so that researchers can work without fighting their infrastructure. That is my day job. At Swisscom I am Component Owner for business-critical Fulfillment ETL -- a distributed system across Oracle, Kafka, Python and Teradata -- and I build the governed data products that analytics and AI teams consume. I carry the data quality and the on-call pager for that estate, which is a different relationship to a system than having built it and moved on.
+
+What draws me to research platform work specifically is that I already build this kind of system for myself. Outside work I built a self-hosted equity signal platform: it ingests daily prices, fundamentals and sentiment, runs a long-only cross-sectional momentum book through scheduled scan and backtest pipelines, and surfaces the gated setups to a dashboard. It is a personal system, not a production service, and I make no claims for its results. But it is the reason I understand what a researcher actually needs from a platform -- fast iteration, reproducible runs, and trust that the data underneath is right -- rather than knowing it only as a requirements document.
+
+I should be straightforward about the shape of my experience: I have built and operated data products and pipelines on a platform, not authored a research platform at firm scale. That step is the reason the role interests me, and the operational judgement I would bring to it is real. I am based in Bern, hold EU citizenship and a Swiss B permit, and need no sponsorship.
+
+\vspace{0.8em}
+I would welcome the chance to talk.
+
+\vspace{1em}
+Kind regards,
+
+\vspace{1.5em}
+Dennis Thiessen
+
+\end{document}