L01: deep-verification fixes (2 source-fidelity corrections)

Verified all 9 cited papers with PDFs against the Charbonneau 2000, Mayor &
Queloz 1995, Wolszczan & Frail 1992, Bryson 2021, Fulton 2017, Greene 2023,
ALMA Partnership 2015, Howell & Pappalardo 2020, and Farley 2022 sources.

Two corrections from the pass:

* HD 209458 b transit-depth caption: the figure caption stated 'about 1.7%'
  but the best-fit transit model from Charbonneau 2000 (Rp = 1.27 RJup, R*
  = 1.1 Rsun) gives a depth of (Rp/Rs)^2 = 1.41%. The 1.7% reading came
  from raw-data scatter rather than the model curve, and was internally
  inconsistent with the formula already in the same caption.

* JWST mission-table entry: changed start year from '2022-' to '2021-' to
  agree with the two other places in the lecture (lines 154 and 444) that
  correctly state the December 2021 launch date.

Per-paper summaries written to ~/git/references/paper-summaries/L01/.
Findings file at ~/.claude/plans/ips_lecture_verification/L01_findings.md.
Adversarial review at ~/.claude/plans/ips_lecture_verification/L01_adversarial.md.
3 unverifiable claim clusters (Sagan1994 quote, IAU2006 criteria text,
NASAFactSheet table values) flagged for manual cross-check by the user.

Author: timlichtenberg

book/01_introduction/introduction.md

@@ -190,7 +190,7 @@ ALMA 1.3 mm continuum image of the protoplanetary disk around the young star HL
 :width: 500px
 :align: center
 
-Discovery transit of HD 209458 b, the first transiting exoplanet ever detected. The relative stellar flux drops by about 1.7% as the planet crosses the disk of its host star, recovering symmetrically afterwards. The depth gives the planet-to-star radius ratio via $\Delta F / F \approx (R_p / R_\star)^2$, and the duration constrains the orbital geometry. Credit: {cite:t}`Charbonneau2000`.
+Discovery transit of HD 209458 b, the first transiting exoplanet ever detected. The relative stellar flux drops by about 1.4% as the planet crosses the disk of its host star, recovering symmetrically afterwards. The depth gives the planet-to-star radius ratio via $\Delta F / F \approx (R_p / R_\star)^2$, and the duration constrains the orbital geometry. Credit: {cite:t}`Charbonneau2000`.
 ```
 
 Today, planetary science integrates astronomy, physics, chemistry, geology, and atmospheric science. It spans scales from dust grains in protoplanetary disks to the demographics of planetary systems across the Galaxy.
@@ -419,7 +419,7 @@ The table below lists landmark missions that have shaped our understanding of th
 | New Horizons | NASA | 2015 | Pluto | First Pluto flyby; revealed geological complexity |
 | Hayabusa2 | JAXA | 2018–2020 | Ryugu | Returned samples from a carbonaceous asteroid |
 | Perseverance | NASA | 2021– | Mars | Sample caching for future return; Ingenuity helicopter |
-| JWST | NASA/ESA/CSA | 2022– | Exoplanets | Atmospheric characterisation of exoplanets |
+| JWST | NASA/ESA/CSA | 2021– | Exoplanets | Atmospheric characterisation of exoplanets |
 | Europa Clipper | NASA | 2024– | Europa | Investigating habitability of Europa's ocean |
 
 ```{figure} figures/cassini_saturn.avif