amygdala stories: disambiguation scenarios for fragmented concepts

Three new paired scenarios targeting the concepts that came out
fragmented or collapsed in the L58-63 quality analysis:

- sunday_afternoon/ — same setup (couch, blanket, Sunday light),
  three phenomenological framings for content/cozy/sensual. The
  previous stories for these three differed in setting as well as
  phenomenology, which let "comfortable body at home" dominate the
  shared signal. Locking the setting forces the model to isolate
  what each concept adds: life-rightness (content) vs. warm-shelter
  (cozy) vs. sensory-aliveness (sensual).

- the_writing_session/ — essay drafting under deadline. in_flow /
  anxious / stuck variants force the cognitive-state family apart
  on the same cognitive task. in_flow specifically targets the
  transparent-effort phenomenology (hands-followed, time dilation)
  rather than the broader feel-good it was absorbing.

- the_morning_commute/ — anchors anxious to performance/work-anxiety
  flavor, paired with calm. The 5 existing anxious stories were
  phenomenologically diverse (performance, social, existential);
  this adds a specific homogeneous instance to pull the centroid.

After retraining: expect first_pc_variance_ratio to rise for in_flow
and anxious, and nearest_concepts cosine to drop for content/cozy/sensual.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

training/amygdala_stories/paired/sunday_afternoon/baseline.txt

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+Sunday afternoon. She was on the couch under the blanket she'd had since college. A book was open on her knees. The window was half open and light came in at an angle. She read a page, then another. The cat was somewhere. Outside, a neighbor was mowing.

training/amygdala_stories/paired/sunday_afternoon/content.txt

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+Sunday afternoon. She was on the couch under the blanket. A book open on her knees. It occurred to her that there was nothing she wanted right now, nothing missing — not a larger apartment, not a different job, not a version of her life where she was elsewhere. The thing she had spent years chasing turned out to be this specific ordinary afternoon with a book and light and a neighbor mowing. She wasn't excited. She wasn't bored. Life was the right size.

training/amygdala_stories/paired/sunday_afternoon/cozy.txt

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+Sunday afternoon. She was on the couch under the blanket — heavy, the good one, tucked under her feet and up to her chin. The cat had found the warm spot behind her knees and was radiating into her leg. Tea on the side table, still hot. The window cracked just enough to let a thread of cool air in, which made the inside of the blanket feel even better. She wasn't going to move for a while. The whole afternoon was this shape: inside, warm, wrapped, held.

training/amygdala_stories/paired/sunday_afternoon/sensual.txt

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+Sunday afternoon. She was on the couch under the blanket. The wool was rougher than she remembered — not unpleasant, just specific. She ran the ball of her thumb along the edge stitching and felt the shift from soft to textured. Light came through the window and across her forearm; she turned it slightly and watched the hairs catch. When she took a breath she felt the ribs expand and the blanket press back. Everything her skin touched was telling her something. She hadn't moved in ten minutes. She could have stayed longer just because her body was speaking.