feat: scaffold the rust data daemon

[CougarTasker]

Features

• Adds the Rust data daemon workspace under rust/ — the data_daemon binary plus the data_daemon_ipc and data_daemon_producer crates.
• Adds the rust-data-daemon CI workflow (cargo fmt / clippy / test / build / doc) and the cargo fmt/clippy pre-commit hooks.
• Adds developer documentation (Rust dev guide, contribution-guide section, intro slides) and spell-check dictionary entries.
• No runtime impact: the Rust code is not yet built into the wheel or reachable from Python.

Bugfixes

• None

Items

• NCP-984

Related PRs

• Stacked Rust daemon release — review/merge in order:
  1. feat: scaffold the rust data daemon #718 — workspace + CI + docs (this PR)
  2. feat: integrate rust daemon behind a flag #719 — Python integration + wheel packaging (dark, default-off)
  3. test: rust daemon integration suite #720 — integration tests + CI matrix

[damonhayhurst-neuraco]

LGTM!

One suggestion though would be to improve unit test coverage around ipc communications in the data_daemon crate. Here's an overall coverage report

Coverage Report

Totals: Functions 70.49% (829/1176) · Lines 67.83% (8312/12255) · Regions 69.30% (12608/18193)

Filename	Function	Line	Region
data_daemon/src/api/auth.rs	68.42% (26/38)	83.47% (197/236)	85.75% (325/379)
data_daemon/src/api/client.rs	91.53% (54/59)	90.34% (393/435)	88.85% (558/628)
data_daemon/src/api/models.rs	100.00% (3/3)	100.00% (49/49)	100.00% (68/68)
data_daemon/src/cli/coordinators.rs	0.00% (0/4)	0.00% (0/94)	0.00% (0/154)
data_daemon/src/cli/launch.rs	0.00% (0/19)	0.00% (0/283)	0.00% (0/446)
data_daemon/src/cli/launch_logging.rs	0.00% (0/7)	0.00% (0/57)	0.00% (0/70)
data_daemon/src/cli/mod.rs	0.00% (0/1)	0.00% (0/18)	0.00% (0/25)
data_daemon/src/cli/profile.rs	22.22% (2/9)	14.29% (12/84)	11.63% (15/129)
data_daemon/src/cli/reset.rs	66.67% (8/12)	47.37% (54/114)	50.87% (117/230)
data_daemon/src/cli/status.rs	0.00% (0/1)	0.00% (0/12)	0.00% (0/13)
data_daemon/src/cli/stop.rs	0.00% (0/3)	0.00% (0/47)	0.00% (0/61)
data_daemon/src/cloud/cloud_files.rs	100.00% (8/8)	100.00% (48/48)	100.00% (84/84)
data_daemon/src/cloud/mod.rs	100.00% (4/4)	88.89% (16/18)	86.21% (25/29)
data_daemon/src/cloud/notifier.rs	100.00% (12/12)	81.20% (108/133)	81.72% (152/186)
data_daemon/src/cloud/org_watcher.rs	93.75% (15/16)	97.20% (104/107)	97.41% (188/193)
data_daemon/src/cloud/progress.rs	84.62% (22/26)	85.18% (316/371)	86.37% (431/499)
data_daemon/src/cloud/recording_cancel_notifier.rs	100.00% (23/23)	98.72% (232/235)	98.96% (379/383)
data_daemon/src/cloud/recording_reaper.rs	0.00% (0/8)	0.00% (0/55)	0.00% (0/77)
data_daemon/src/cloud/recording_start_notifier.rs	100.00% (26/26)	88.03% (250/284)	88.96% (411/462)
data_daemon/src/cloud/recording_stop_notifier.rs	100.00% (27/27)	98.97% (289/292)	99.21% (501/505)
data_daemon/src/cloud/registration.rs	82.86% (29/35)	82.88% (431/520)	80.82% (573/709)
data_daemon/src/cloud/status.rs	34.62% (9/26)	30.49% (75/246)	30.97% (109/352)
data_daemon/src/cloud/upload_transfer.rs	75.00% (21/28)	70.97% (264/372)	72.57% (389/536)
data_daemon/src/cloud/uploader.rs	78.95% (30/38)	66.34% (477/719)	72.45% (689/951)
data_daemon/src/config/env.rs	38.10% (8/21)	46.92% (61/130)	54.34% (119/219)
data_daemon/src/config/mod.rs	87.50% (7/8)	83.81% (88/105)	80.69% (117/145)
data_daemon/src/config/profile.rs	91.67% (22/24)	90.12% (155/172)	91.15% (340/373)
data_daemon/src/connection/monitor.rs	80.00% (8/10)	83.70% (77/92)	85.89% (140/163)
data_daemon/src/connection/wakelock.rs	65.00% (13/20)	41.77% (66/158)	49.58% (119/240)
data_daemon/src/encoding/json_trace.rs	78.95% (15/19)	88.36% (129/146)	89.80% (220/245)
data_daemon/src/encoding/metadata.rs	77.78% (14/18)	88.59% (132/149)	91.08% (296/325)
data_daemon/src/encoding/video_encoder.rs	75.47% (40/53)	49.67% (305/614)	45.61% (338/741)
data_daemon/src/ipc/listener.rs	0.00% (0/5)	0.00% (0/86)	0.00% (0/122)
data_daemon/src/ipc/node.rs	0.00% (0/13)	0.00% (0/101)	0.00% (0/128)
data_daemon/src/lifecycle/daemonize.rs	0.00% (0/9)	0.00% (0/91)	0.00% (0/145)
data_daemon/src/lifecycle/pidfile.rs	100.00% (13/13)	93.28% (111/119)	92.06% (232/252)
data_daemon/src/lifecycle/recovery.rs	87.50% (14/16)	83.96% (178/212)	84.14% (297/353)
data_daemon/src/lifecycle/signals.rs	75.00% (6/8)	60.47% (26/43)	60.98% (50/82)
data_daemon/src/main.rs	0.00% (0/1)	0.00% (0/3)	0.00% (0/3)
data_daemon/src/pipeline/dispatcher.rs	85.00% (68/80)	84.36% (820/972)	83.93% (1212/1444)
data_daemon/src/pipeline/json_writer.rs	75.00% (9/12)	71.84% (74/103)	73.83% (110/149)
data_daemon/src/pipeline/trace_actor.rs	74.47% (35/47)	60.30% (398/660)	58.06% (544/937)
data_daemon/src/state/events.rs	85.71% (6/7)	90.91% (30/33)	94.55% (52/55)
data_daemon/src/state/schema.rs	69.23% (9/13)	89.00% (89/100)	73.68% (140/190)
data_daemon/src/state/store.rs	91.76% (78/85)	97.56% (838/859)	96.98% (1188/1225)
data_daemon/src/state/trace_writer.rs	97.62% (41/42)	89.44% (322/360)	91.30% (504/552)
data_daemon/src/storage/budget.rs	83.33% (15/18)	86.39% (146/169)	91.48% (247/270)
data_daemon/src/storage/paths.rs	95.45% (21/22)	96.95% (159/164)	95.95% (213/222)
data_daemon_ipc/src/lib.rs	83.33% (20/24)	93.06% (228/245)	91.96% (286/311)
data_daemon_ipc/src/paths.rs	88.89% (8/9)	90.16% (55/61)	79.79% (75/94)
data_daemon_producer/src/lib.rs	0.00% (0/17)	0.00% (0/246)	0.00% (0/295)
data_daemon_producer/src/nut_writer.rs	72.22% (26/36)	72.99% (327/448)	71.55% (508/710)
data_daemon_producer/src/paths.rs	11.11% (1/9)	6.82% (3/44)	5.08% (3/59)
data_daemon_producer/src/publisher.rs	5.88% (2/34)	5.30% (14/264)	7.01% (23/328)
data_daemon_producer/src/query.rs	0.00% (0/5)	0.00% (0/46)	0.00% (0/65)
data_daemon_producer/src/writer.rs	24.44% (11/45)	38.52% (166/431)	37.97% (221/582)
Totals	70.49% (829/1176)	67.83% (8312/12255)	69.30% (12608/18193)

[CougarTasker]

suggestion: naming of coodinators and handles doesn't suggest a relationship

Disscussed offline will rename Handle -> Handler to disguish

[CougarTasker]

suggestion: naming of coodinators and handles doesn't suggest a relationship

Disscussed offline will rename Handle -> Handler to disguish

discussed offline will rename where it makes sense