Drop role_order; replace with simpler pi: true flag

role_order was a numeric scale (1=PI, 2=manager, 3=specialist, ...)
that lost meaning once we switched to last-name alphabetical sorting.
The only remaining use was identifying the PI to pin to the end of
the current-members list. Replaced with an explicit boolean pi: true
flag on Rhiju Das only — clearer intent, no semantic numeric scale to
remember.

- _people/*.md: removed role_order from all 8 current entries; added
  pi: true to rhiju-das.md.
- people.md: where_exp 'p.role_order != 1' -> 'p.pi != true', and
  where: 'role_order', 1 -> where: 'pi', true.
- tools/scrape_content.py and tools/migrate_people.py: drop role_order
  derivation, replace with _is_pi() returning a boolean.
- CONTRIBUTING.md: drop the role_order section; document pi: true as
  the optional flag for the PI.

Author: rhiju

CONTRIBUTING.md

@@ -31,31 +31,19 @@ You'll need a (free) GitHub account, and Rhiju (or any DasLab org admin) needs t
    role: Postdoctoral Fellow, Biochemistry
    photo: /assets/images/people/jane-doe.jpg
    status: current
-   role_order: 4
+   last_name: doe
    ---
    ```
 
 5. Click **"Commit changes"** at the bottom.
 
-### What goes in `role_order`
-
-Lower numbers sort to the top of the people grid. Pick the first that applies:
-
-- **1** — Principal Investigator
-- **2** — Lab manager
-- **3** — Research specialist / scientist
-- **4** — Postdoctoral fellow
-- **5** — Ph.D. student
-- **6** — Rotation student
-- **7** — Undergraduate / intern
-- **9** — Other
-
-Within the same `role_order`, members are sorted alphabetically by name.
+The `last_name` is used for sorting (alphabetical, case-insensitive) — write it lowercased. Members are listed alphabetically by `last_name`. The principal investigator is pinned to the end (see below).
 
 ### Optional fields
 
 - `cv_url:` — link to a CV (e.g., a Dropbox link)
 - `profile_url:` — link to a Stanford profile page
+- `pi: true` — pins this person to the end of the current-members list. Only the principal investigator should have this.
 
 ---
 
@@ -72,7 +60,7 @@ When a lab member leaves, you only edit one file — no need to move it between
    end_year: 2026
    ```
 
-   …and remove `role_order` (it's only used for current members). Replace it with the year they left.
+   `end_year` is the year they left. (You can also remove `pi`, `cv_url`, etc. if no longer relevant — but `last_name` should stay; it sorts within their year.)
 
 4. Update the `role` line to include the date range, e.g.:
 

_people/ann-kladwang.md

@@ -3,6 +3,5 @@ name: Ann Kladwang
 role: Research Specialist II Biochemistry
 photo: /assets/images/people/AnnK.jpeg
 status: current
-role_order: 3
 last_name: kladwang
 ---

_people/chaitanya-joshi.md

@@ -3,6 +3,5 @@ name: Chaitanya Joshi
 role: Postdoctoral Associate Biochemistry
 photo: /assets/images/people/ChaitanyaJ.png
 status: current
-role_order: 4
 last_name: joshi
 ---

_people/hamish-blair.md

@@ -3,6 +3,5 @@ name: Hamish Blair
 role: Ph.D. Student Mathematics
 photo: /assets/images/people/HamishB.jpg
 status: current
-role_order: 5
 last_name: blair
 ---

_people/jigyasa-verma.md

@@ -3,6 +3,5 @@ name: Jigyasa Verma
 role: Postdoctoral Associate Biochemistry Department
 photo: /assets/images/people/JigyasaV.jpg
 status: current
-role_order: 4
 last_name: verma
 ---

_people/matthew-liu.md

@@ -3,6 +3,5 @@ name: Matthew Liu
 role: Ph.D Rotation Student Computer Science
 photo: /assets/images/people/MatthewL.jpg
 status: current
-role_order: 6
 last_name: liu
 ---

_people/rachael-kretsch.md

@@ -3,6 +3,5 @@ name: Rachael Kretsch
 role: "Postdoctoral associate Biophysics Joint: Wah Chiu Lab"
 photo: /assets/images/people/RachaelK.jpg
 status: current
-role_order: 4
 last_name: kretsch
 ---

_people/rhiju-das.md

@@ -5,6 +5,6 @@ photo: /assets/images/people/RhijuD_2026.jpg
 cv_url: "https://www.dropbox.com/scl/fi/ga8tuc3djn4fvwboxu33r/RhijuDas_Curriculum-Vitae.pdf?rlkey=grz747a7kzf8nv8edyoilr1o6&dl=0"
 profile_url: "https://profiles.stanford.edu/rhiju-das"
 status: current
-role_order: 1
 last_name: das
+pi: true
 ---

_people/vivian-wu.md

@@ -3,6 +3,5 @@ name: Vivian Wu
 role: Lab Manager HHMI
 photo: /assets/images/people/VivianW.jpg
 status: current
-role_order: 2
 last_name: wu
 ---

people.md

@@ -7,8 +7,8 @@ permalink: /people/
 ---
 
 {% assign all_current = site.people | where: "status", "current" %}
-{% assign non_pi = all_current | where_exp: "p", "p.role_order != 1" | sort_natural: "last_name" %}
-{% assign pi     = all_current | where: "role_order", 1 %}
+{% assign non_pi = all_current | where_exp: "p", "p.pi != true" | sort_natural: "last_name" %}
+{% assign pi     = all_current | where: "pi", true %}
 {% assign current = non_pi | concat: pi %}
 
 {% comment %}